Devices and methods for removing material from a patient

ABSTRACT

A containing element is used to capture material in a blood vessel for removal. The containing element is positioned within a constraining catheter while it is advanced through the blood vessel. A filament is coupled to the containing element which assists in opening and/or closing the containing element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/790,268, filed Feb. 13, 2020, and titled “Devices and Methods forRemoving Material From a Patient”; which is a continuation of U.S.patent application Ser. No. 16/443,820, filed Jun. 17, 2019, now U.S.Pat. No. 10,624,659, and titled “Devices and Methods for RemovingMaterial From a Patient”; which is a continuation of PCT/US2019/021943,filed Mar. 12, 2019, and titled “Devices and Methods for RemovingMaterial From a Patient”; which claims the priority benefit of each ofU.S. Provisional Patent Application No. 62/641,948, filed Mar. 12, 2018,titled “Treatment Device and Method” and U.S. Provisional PatentApplication No. 62/793,498, filed Jan. 17, 2019, titled “TreatmentDevice and Method”, all of which are incorporated herein by reference intheir entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference in their entirety, as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference in its entirety.

TECHNICAL FIELD

This disclosure relates generally to the field of surgery, and morespecifically to the field of interventional radiology. Described hereinare devices and methods for removing material from a patient.

BACKGROUND

Minimally invasive endovascular techniques have come to the forefront inthe safe and expeditious use of embolectomy devices for thromboembolicclot extraction. Currently employed devices generally extract the clotusing a combination of balloons, graspers, aspiration, and wireretrievers. These devices attempt to remove the clot in vivo byattaching to it and then pulling it through the vascular lumen and outof the body. With these devices the thrombus is typically not fullycontained and if fragments of the clot break away, they may become newemboli in the blood stream. That is to say that existing devicestypically maintain partial or full exposure of the thrombus within thevascular lumen and when clot extraction is attempted the “bare thrombus”can pose a threat of fragmentation or partial clot dislodgement whichcan predispose a patient to inadvertent distal embolization, non-targetterritory embolization or incomplete thrombus extraction.

Additionally, in order to limit the blood flow in the clotted vesselduring clot removal, many procedures utilize a variety of flow arresttechniques such as balloon-assisted proximal vessel occlusion tominimize antegrade flow in an effort to exclude distal clotfragmentation during clot extraction. Mechanical or assisted suctiontechniques are oftentimes utilized simultaneously via the balloon flowarrest catheter to capture any potential embolic debris during clotextraction. However, complete flow arrest in the brain arteries is oftendifficult due to extensive intracranial collaterals (e.g. Circle ofWillis), limiting the efficacy and utility of proximal flow arrest andsuction in the carotid circulation. Even limited blood flow can create asignificant risk of clot fragmentation and distal migration of clotduring extraction.

Completely encasing the clot captured within the stent-retriever byisolating the thromboembolism and excluding it from the vascular flowchannel would eliminate or markedly reduce the risk of embolization.

SUMMARY

The present invention is directed to devices and methods for removingmaterial from a blood vessel. In a specific application, the devices andmethods are used to capture and remove material from the cerebralvasculature. The device includes a capture element which is collapsedand loaded into a delivery catheter which is advanced to a vascularlocation. The capture element is then deployed in a position to receiveand contain material for removal. A clot retrieving element (such as astent retriever) may be used to engage the material to be removed andassist in moving the material into the capture element.

The capture element is contained within a chamber (which may be a lumen)in the delivery catheter when advanced through the vasculature. Thecapture element has a distal opening at a distal end and a sidewallextending proximally from the distal opening. The distal opening ismoved to an open position to receive the material. The distal openingdefines a perimeter which is used to define aspects of the inventiondescribed below.

A first filament is coupled to the capture element to manipulate thecapture element. When the capture element is positioned at or near thelocation where the material is to be removed, the capture element isreleased from the chamber by moving the capture element to a positionoutside the chamber. The capture element may be moved out of the chamberby manipulating the delivery catheter and/or the capture element.

When the capture element is released, the first filament may support theopen position of the distal opening. For example, the first filament mayhave a predetermined shape which supports the open position. Thepredetermined shape may extend around at least 120 degrees, at least 150degrees or at least 260 degrees, around the distal opening in the openposition when viewed along a longitudinal axis defined by the captureelement. The predetermined shape of the first filament may form a firstconcave portion (facing the longitudinal axis) which supports and movesthe distal opening to the open position when the capture element isreleased. The first concave portion may generally lie in a plane whichforms an angle with the first arm of 45-135 degrees in an unbiasedposition. When the capture element is closed, the plane forms an anglewith the first arm of 135-180 degrees.

Stated another way, the concave portion has a shape larger than anunbiased shape of the distal opening so that the concave portion biasesthe distal opening toward the open position. The concave portion may berestrained by the open position of capture element so that the concaveportion biases the distal opening toward the open position.

When the capture element is released and the distal opening is open, thematerial is then engaged (with a clot engaging element such as a stentretriever) and passed through the distal opening and into the captureelement. The first filament may be coupled to the delivery catheter sothat the first filament moves proximally relative to the capture elementwhen the capture element moves to the released position and when thecapture element is closed. Manipulation of the first filament with thedelivery catheter provides advantages over systems that require thetension element to extend out of the patient (such as lower tensionforce required at the proximal end resulting in lower forces exerted onblood vessels through which the tension element extends). Of course, thefirst filament may also extend out of the patient and be manipulatedindependent of the delivery catheter without departing from numerousaspects of the present invention.

Once the material is contained within the capture element, the captureelement is moved to a closed position in which the distal opening isreduced in size to prevent the material from escaping through the distalopening as the capture element is removed and/or moved into the deliverycatheter or another catheter or sheath for removal from the patient. Thedistal opening may be closed by tensioning the first filament. The firstfilament may have a first arm and a second arm which are both tensioned.The first and second arms may extend from the first and second ends ofthe concave portion, respectively. Further aspects of the presentinvention will now be described with reference to the various positionsof the first filament and the capture element and the basic method stepsdescribed above.

When the capture element and first filament are advanced through theblood vessel, the first filament may have a first leading portion whichextends from the distal end of the capture element within the deliverycatheter. The first leading portion may have a length (which may form afirst loop) which extends from the distal end of the capture element atleast 30%, or at least 50%, of an effective diameter of the perimeter ofthe distal opening in the open position when moving to the openposition. The first leading portion may be free of attachments to thecapture element and may extend distally at least 1.5 mm from the distalend of the capture element as the capture element is released (and whilethe distal opening is moving toward the open position). The term “loop”as it pertains to the leading portion does not require a closed loop andmerely requires a segment having both ends extending outwardly from thedistal end of the delivery element. As used herein, the effectivediameter is the equivalent diameter of a circle having the same area asthe distal opening (the area circumscribed by the perimeter) or otherreference area or cross-section.

The first filament may be positioned at a relatively distal locationwhen advanced through the vasculature by the delivery catheter. Thefirst filament defines a working length which is the length of the firstfilament positioned within 10 cm of the distal end of the captureelement. The working length of the first filament includes the firstarm, the second arm and the concave portion but may include just one armin some embodiments and may omit the concave portion in withoutdeparting from the scope of the invention. The working length of thefirst filament changes by less than 70% of the effective diameter of thedistal opening in the open position when the capture element moves fromthe collapsed position to the released position.

The first filament (and optionally the first leading portion) may alsoengage an inner surface of the sidewall of the capture element when thefilament moves to the released position. The first filament may alsoapply (exert) an outward force to the inner surface of the sidewall overa longitudinal length of at least 2 cm and may contact the inner surfacethrough an angle of at least 180 degrees when viewed along thelongitudinal axis.

When the capture element is closed by tensioning the first and secondarms, the concave portion is deformed to reduce the size of the distalopening. The concave portion may be elastically deformed when and may beformed of a superelastic material deformed into a superelastic state.The effective diameter of the distal opening may reduce in size by atleast 80% when moving to the closed position (and may be no more than 1mm in the closed position).

Tensioning the first filament (specifically the first and second arms)may also invert a portion of the sidewall at the distal end. Invertingof the sidewall also moves the distal opening proximally to a positionsurrounded by the sidewall. The sidewall may resist inverting so that aradially inward force is exerted on the inverted portion which istransmitted through the sidewall to bias the distal opening toward theclosed position.

The sidewall of the capture element may also include an expandableportion. The expandable portion may be at least 10 mm long and within 10mm from the distal end of the capture element. The expandable portionmay exert a radially outward force on the vessel wall when tensioningthe first filament to close the capture element. The expandable portionmay be naturally biased outward due to the physical properties and shapeof the sidewall. Alternatively, the first filament may move and/orassist the sidewall and distal opening to the open position.

The expandable portion may be expanded by the first filament beyond anunbiased shape so that an effective diameter of the expandable portionincreases by at least 10%. Stated another way, when the capture elementis moved to the closed position the first filament is tensioned to exertan outward force on the expandable portion and may increase a radiallyoutward force on the vessel wall by at least 10%. The sidewall of thecapture element may also have a distal portion which reduces in lengthwhen the capture element is closed. The distal portion may extend 10 mmfrom the distal end and reduces in length longitudinally by at least 20%when the capture element moves to the closed position. The distalportion may also expand in accordance with the expandable portiondescribed below.

In some embodiments, the first concave portion may form a closed loopwith only the first arm extending from the closed loop. In otherembodiments a second filament is coupled to the capture element. Thesecond filament may have all features, aspects and uses as the firstfilament and all such features, aspects and uses are incorporated forthe second filament. For example, the second filament may have a secondleading portion which may have any of the characteristics, features anduses of the first leading portion of the first filament. The secondfilament may be coupled to the first filament and may even be beingintegrally formed with the first filament. The first concave portion anda second concave portion formed by the second filament may each extend90-180 degrees when the capture element is in the open position.

The foregoing is a summary, and may be limited in detail. Theabove-mentioned aspects, as well as other aspects, features, andadvantages of the present technology are described below in connectionwith various embodiments, with reference made to the description, claimsand accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of the device in an isometric view.

FIG. 2A illustrates a first embodiment of the filament predeterminedshape.

FIG. 2B illustrates a second embodiment of the filament predeterminedshape.

FIG. 2C illustrates a third embodiment of the filament predeterminedshape.

FIG. 2D illustrates a fourth embodiment of the filament predeterminedshape.

FIG. 2E illustrates a first embodiment of the filament predeterminedshape.

FIG. 2F illustrates a first embodiment of the filament predeterminedshape.

FIG. 2G illustrates a first embodiment of the filament predeterminedshape.

FIG. 2H illustrates a first embodiment of the filament predeterminedshape.

FIG. 2I illustrates a first embodiment of the filament predeterminedshape.

FIG. 2J illustrates a first embodiment of the filament predeterminedshape.

FIG. 2K illustrates a first embodiment of the filament predeterminedshape.

FIG. 3 illustrates a detailed view of the distal end of the containerelement.

FIG. 4A illustrates an intermediate catheter within a vessel whichincludes a clot.

FIG. 4B illustrates a microcatheter traversing the clot.

FIG. 4C illustrates the microcatheter retracted and a clot engagementelement engaged with the clot.

FIG. 4D illustrates the intermediate catheter retracted and aconstraining catheter in place.

FIG. 4E illustrates the constraining catheter beginning to be retractedand the container element partially deployed.

FIG. 4F illustrates the constraining catheter further retracted and thecontainer element further deployed.

FIG. 4G illustrates the constraining catheter further retracted and thecontainer element further deployed.

FIG. 4H illustrates the constraining catheter fully retracted and thecontainer element fully deployed.

FIG. 4I illustrates the clot engagement element and clot partiallyretracted into the container element.

FIG. 4J illustrates the clot engagement element and clot fully retractedinto the container element.

FIG. 4K illustrates the distal end of the container element partiallyclosed.

FIG. 4L illustrates the distal end of the container element furtherclosed.

FIG. 4M illustrates the distal end of the container element inverted.

FIG. 4N illustrates the distal end of the container element furtherinverted.

FIG. 4O illustrates the microcatheter and clot engagement elementretracted.

FIG. 4P illustrates the constraining catheter and container elementbeginning to be retracted from the vessel.

FIG. 5A illustrates a detailed view of the distal end of the containerelement open.

FIG. 5B illustrates a detailed view of the distal end of the containerelement partially closed.

FIG. 5C illustrates a detailed view of the distal end of the containerelement further closed.

FIG. 5D illustrates a detailed view of the distal end of the containerelement inverted.

FIG. 5E illustrates a detailed view of the distal end of the containerelement further inverted.

FIG. 6A illustrates an embodiment of the device with an aspirationcatheter.

FIG. 6B illustrates the aspiration catheter advanced toward the clot.

FIG. 6C illustrates the clot drawn toward the aspiration catheter.

FIG. 6D illustrates the aspiration catheter and clot retracted into thecontainer element.

FIG. 6E illustrates the distal end of the container element partiallyclosed.

FIG. 6F illustrates the distal end of the container element furtherclosed.

FIG. 6G illustrates the distal end of the container element inverted.

FIG. 6H illustrates the distal end of the container element furtherinverted.

FIG. 7A illustrates a constraining catheter.

FIG. 7B illustrates a filament advancing out of the constrainingcatheter.

FIG. 7C illustrates the filament further advanced out of theconstraining catheter.

FIG. 7D illustrates a container element advancing out of theconstraining element.

FIG. 7E illustrates the filament forming an open distal end of thecontainer element.

FIG. 7F illustrates the container element further advanced out of theconstraining element.

FIG. 7G illustrates the container element further advanced out of theconstraining element.

FIG. 8A illustrates an embodiment with an askew plane filament perimeterin a constraining catheter.

FIG. 8B illustrates an embodiment with an askew plane filament perimeterdeployed from a constraining catheter.

FIG. 9A illustrates an embodiment of part of the invented device withina simulated vessel.

FIG. 9B illustrates the distal end of the container element partiallyclosed and retracted.

FIG. 9C illustrates the distal end of the container element furtherclosed and retracted.

FIG. 9D illustrates the distal end of the container element furtherclosed and retracted.

FIG. 9E illustrates the container element with the distal end of thedevice substantially closed.

FIG. 9F illustrates a perspective view of the container element.

FIG. 10A illustrates an embodiment of the container element inside anintermediate catheter.

FIG. 10B illustrates the container element with the intermediatecatheter retracted and the distal opening closed.

FIG. 10C illustrates the container element with the intermediatecatheter retracted and the distal opening open.

FIG. 11A illustrates a vessel with a clot and an intermediate catheterinside the vessel.

FIG. 11B illustrates a microcatheter extending from the intermediatecatheter and a guidewire traversing the clot.

FIG. 11C illustrates the microcatheter traversing the clot.

FIG. 11D illustrates the guidewire removed from the patient.

FIG. 11E illustrates a stent retriever inserted into the microcatheterand traversing the clot.

FIG. 11F illustrates the microcatheter retracted and the stent retrievercapturing the clot.

FIG. 11G illustrates the intermediate catheter and microcatheter removedfrom the patient.

FIG. 11H illustrates an intermediate catheter inserted into the vesselwith the container element inside the intermediate catheter.

FIG. 11I illustrates the intermediate catheter retracted and thecontainer element in an open configuration inside the vessel.

FIG. 11J illustrates the stent retriever and clot pulled within thecontainer element.

FIG. 11K illustrates the container element in a closed configuration.

FIG. 12A illustrates an embodiment of the device with a filamentcatheter with the distal opening in an open position.

FIG. 12B illustrates an embodiment of the device with a filamentcatheter with the distal opening in a closed position.

FIG. 13A illustrates an embodiment of the device with a flap in the openposition.

FIG. 13B illustrates an embodiment of the device with a flap in thepartially closed position.

FIG. 13C illustrates an embodiment of the device with a flap in theclosed position.

FIG. 13D illustrates an embodiment of the device with multiple flaps inthe open position.

FIG. 14A illustrates an embodiment of the device with a filament excesslength in the constrained position.

FIG. 14B illustrates an embodiment of the device with a filament excesslength in the deployed position.

FIG. 14C illustrates an embodiment of the device with a filament excesslength in the closed position.

DETAILED DESCRIPTION

In FIG. 1 , a device 2 to contain and remove material from a bloodvessel is shown. The device 2 includes a container element 4, a firstfilament 6, and a constraining catheter 8. The device 2 is shown in agenerally deployed configuration with the container element 4unrestricted by the constraining catheter 8 and the first filaments isnot under significant tension. The various configurations and proceduralsteps of the device 2 will be described in greater detail below. Aspectsof the present invention are described with reference to a single orlimited number of embodiments, however, it is understood that allfeatures, aspects and methods are incorporated into all applicableembodiments described herein even though not expressly mentioned or setforth.

The container element 4 has a vessel diameter portion 10 and a smalldiameter portion 12 with a proximal funnel area 14 between them. Thecontainer element 4 is connected to the first filament 6 toward a distalend 16 and the constraining catheter 8 toward a proximal end 18. Theconnection of the first filament 6 toward the distal end is configuredsuch that when proximal tension is applied to the first filament 6, adistal opening 20 of the container element 4 reduces in size from anopen position of FIG. 5A to a closed position of FIG. 5E and may alsomove proximally as described below. The open position defines aperimeter of the distal opening 20. The constraining catheter 8 mayslide axially along the length of the container element 4 and isconfigured to constrict the container element 4 and position thecontainer element 4 within a chamber 22 (which may be a lumen 24). Aswill be shown in the images below, as the constraining catheter 8 slidesdistally over the container element 4, the container element 4constricts and enters the constraining catheter 8 to load the containerelement 4 within the constraining catheter 8 for delivery through thevasculature. The entirety of the container element 4 may fit within theconstraining catheter 8. As the constraining catheter 8 is then movedproximally relative to the container element 4, the container element 4is configured to extend out of the constraining catheter 8 and mayexpand as defined by its unrestricted shape to deploy the containerelement 4 at or near the desired location to remove material. Thecontainer element 4 has a lumen 7 through which a clot retrieval devicemay be passed as detailed herein.

The constraining catheter 8 is advanced through a blood vessel with thecontainer element 4 positioned in the chamber 22 and held in thecollapsed position. The container element 4 has a sidewall 26 extendingproximally from the distal opening 20 which surrounds and contains thematerial. The first filament 6 is coupled to the container element 4 tomanipulate the container element 4 as described herein. The firstfilament 6 is also in a collapsed position when the container element 4is collapsed within the chamber 22 of the constraining catheter 8. Thefirst filament 6 may include a first arm 28 coupled to a first end 32 ofa concave portion 34 and a second arm 30 coupled to a second end 36 ofthe concave portion 34. The concave portion 34 faces a longitudinal axisLA defined by the container element 4. As used herein, the longitudinalaxis LA follows the geometry of the container element 4 at a geometriccenter of the sidewall 26 and may take any shape such as curved orsegmented linear sections and may be substantially by the shape of thevasculature rather than an unbiased shape of the container element 4 inuse. The concave portion 34 may support the open position of the distalopening 20 as described in further detail below.

The container element 4 and first filament 6 may be advanced through theblood vessel with the first filament 6 having a first leading portion 38which extends from the distal end 16 of the container element 4 in thecollapsed position. The first leading portion 38 may have a length Lwhich extends from the distal end 16 of the container element 4 by atleast 30%, or at least 50%, of an effective diameter ED of a perimeter Pof the distal opening 20 in the open position. The first leading portion38 may be free of attachments to the container element 4 and may extenddistally at least 1.5 mm from the distal end 16 of the container element4 in the collapsed position. The first leading portion 38 may form afirst loop 40 which extends beyond the distal end 16 of containerelement 4.

The container element 4 may also be advanced through the vasculaturewith the first filament 6 defining a working length WL which ispositioned at a relatively distal location when collapsed. The workinglength WL is defined as the length of the first filament 6 positionedwithin 10 cm of the distal end 16 of the container element 4. Forexample, the working length WL may include the combined length of thefirst arm 28, the second arm 30 and the concave portion 34 within 10 cmof the distal end 16. In an aspect of the invention, the working lengthWL of the first filament 6 changes by less than 70% of the effectivediameter ED of the distal opening 20 in the open position when thecontainer element 4 moves from the collapsed position to the releasedposition. In a specific embodiment, the working length WL may be about11.5 cm in the collapsed position and about 11.5 cm when the distalopening 20 is open.

The first leading portion 38 and working length WL both contribute toreducing the required length of the first filament 6 that must be drawndistally as part the working length WL to release the container element4. The required length of the first filament 6 to be drawn distally maybe further reduced by coupling the first filament 6 to the constrainingcatheter 8 so that the first filament 6 moves proximally with theconstraining catheter 8 relative to the container element 4 whenreleasing the container element 4 and when closing the distal opening20. Coupling the first filament 6 (specifically the first and secondarms 28, 30) to the constraining catheter 8 in this manner furtherreduces the required length of the first filament 6 that must bemanipulated since the first filament 6 needn't extend completely out ofthe patient like many conventional devices. Of course, the firstfilament 6 may also be independent of the constraining catheter 8 andextend out of the patient without departing from numerous aspects of thepresent invention.

The container element 4 is moved to a released position outside thechamber 22 by moving the container element 4, the constraining catheter8 or both. The first filament 6 may move to the released position whilethe distal opening 20 simultaneously moves to the open position as thecontainer element 4 is moved/positioned outside of the chamber 22.Simultaneous release of the sidewall 26 and opening of the distalopening 20 may be accomplished by coupling the first filament 6(specifically the proximal end of the first and second arms 28, 30) tothe constraining catheter 8 as described above. Alternatively, thedistal opening 20 may be separately opened using the first filament 6 orsome other structure after the container element 4 has been releasedwithout departing from numerous aspects of the invention. Thus, the openposition may be achieved in any suitable manner in accordance with thepresent invention although aspects of the present invention provide forthe first filament 6 to support the open position as now described.

The first filament 6 may be positioned and coupled to the containerelement 4 so that the natural unbiased shape (such as the shape of theconcave portion 34) supports the open position of the distal opening 20.For example, the first filament 6 may have a predetermined shape 46which defines a filament perimeter 48 which supports the open positionof the container element 4. The predetermined shape 46 may extend aroundat least 120 degrees, at least 150 degrees or at least 260 degrees,around the distal opening 20 in the open position when viewed along thelongitudinal axis LA. Stated another way, the first filament 6 may formthe first concave portion 34 (oriented facing the longitudinal axis LA)which supports and moves the distal opening 20 to the open position whenthe container element 4 is released. Stated yet another way, the concaveportion 34 has a shape larger than an unbiased shape of the distalopening 20 so that the concave portion 34 biases the distal opening 20toward the open position. Stated still another way, the concave portion34 may be restrained by the open position of container element 4 so thatthe concave portion 34 biases the distal opening 20 toward the openposition. The first leading portion 38 may form the predetermined shapesuch as the concave portion 34. The first concave portion 34 maygenerally lie in a plane P which forms an angle A with the first arm 28of 45-135 degrees in an unbiased position as shown in FIG. 9A. When thecontainer element 4 is closed, the plane P forms the angle A with thefirst arm 28 of 135-180 degrees. The first concave portion 34 may alsoform a closed loop 50 which moves the distal opening 20 toward the openposition when the container element 4 is in the released position asshown in FIG. 9A.

When the container element 4 is opened by the first filament 6, thefirst leading portion 38 may move into the container element 4 and formthe concave portion 34 or, alternatively, move into the containerelement 4 and engage an inner surface 52 of the container element 4.Furthermore, the first filament 6 may apply an outward force to theinner surface 52 of the sidewall 26 over a longitudinal length of atleast 2 cm of the container element 4 in the released position which mayhelp anchor the device 2 when the material is moved into the containerelement 4 through the distal opening 20. The first filament 6 may alsoapply the outward force to the inner surface 52 over an angular extentof at least 180 degrees when viewed along the longitudinal axis LA. Thefirst filament 6 (such as the first and second arms 28, 30) may also besubstantially straight and may not apply an outward force to thesidewall 26 without departing from numerous aspects of the invention.

Once the distal opening 20 is in the open position, a clot engagingelement 58 (which may engage in any suitable manner such as mechanicalor suction engagement) is used to engage and, if necessary, dislodge thematerial to be removed. The material is then passed through the distalopening 20 and into the container element 4 by manipulating the clotengaging element 58, the container element 4, the first filament 6 orany combination thereof.

After the material to be removed is contained within the containerelement 4, the container element 4 is closed by tensioning the firstfilament 6 (such as the first arm 28 and second arm 30). The distalopening 20 may reduce in size from the open position so that theeffective diameter ED is reduced by at least 80%. Stated another way,the effective diameter ED in the closed position may be no more than 1mm.

The concave portion 34 may also be deformed when the first filament 6 istensioned to close the distal opening 20. The first filament 6 (such asthe concave portion 34) may be formed of a superelastic material whichis elastically deformed when the distal opening 20 is closed. Theconcave portion 34 may also be plastically deformed or may be a simpletension element without departing from aspects of the invention.

The sidewall 26 of the container element 4 may also include anexpandable portion 60 which may expand into engagement with the vessel80 when the distal opening 20 is closed. The expandable portion 60 maybe at least 10 mm long and within 10 mm from the distal end 16 of thecontainer element 4. The expandable portion 60 may exert a radiallyoutward force on the vessel wall when the container element 4 is closedby tensioning the first filament 6. The expandable portion 60 may beexpanded beyond an unbiased shape by the first filament 6, for example,an effective diameter ED of the sidewall 26 along the expandable portion60 may increase by at least 10% compared to an unbiased condition.Stated another way, when the container element 4 is moved to the closedposition the first filament 6 causes an outward force on the expandableportion 60 which increases a radially outward force on the vessel wallby at least 10%.

The sidewall 26 of the container element 4 may also have a distalportion DP which reduces in length when the container element 4 isclosed. The distal portion DP may extend 10 mm from the distal end 16and reduces in length longitudinally by at least 20% when the containerelement 4 moves to the closed position. The distal portion DP may alsoexpand in accordance with the expandable portion 60 and be fully orpartially coextensive with the expandable portion 60.

The first filament 6 may also move proximally when the distal opening 20is closed and may also move the distal opening 20 proximally as shown inFIGS. 9A-9F. The first filament 6 may be coupled to the constrainingcatheter 8 so that the first filament 6 is manipulated by theconstraining catheter 8 and moves proximally with the constrainingcatheter 8 relative to the container element 4 when the containerelement 4 is released and when it is closed. In this manner, the firstfilament 6 is manipulated by the constraining catheter 8 which providesthe advantages described herein such as a reduced length of the firstfilament 6 and possibly reduced forces on the vessel 80 when tensioningthe first filament 6.

When the distal opening 20 is closed, the sidewall 26 may form aninverted IP portion which also moves the distal opening 20 to a positionsurrounded by the sidewall 26 (when viewed along the longitudinal axisLA). The sidewall 26 may also apply a radially inward force on theinverted portion IP (which is transmitted through the sidewall 26) tobias the distal opening 20 toward the closed position. The distalopening 20 may also invert when moving to the closed position or mayremain uninverted with a small portion of the distal end of the sidewall26.

The device 2 may also include a second filament 6A coupled to thecontainer element 4 as shown in FIG. 2K wherein the same or similarreference numbers refer to the same or similar features as the firstfilament and all relevant features are incorporated here as previouslymentioned. The second filament 6A may have a second leading portion 42which distally extends beyond the distal end 16 of the container element4 in the collapsed position. The second leading portion 42 extends atleast 1.5 mm from the distal end 16 of the container element 4. Thesecond leading portion 38A has a length which extends from the distalend 16 of the container element 4 which is at least 30%, and may be atleast 50%, of an effective diameter of the perimeter of the distalopening 20 in the open position.

The second filament 6A may be coupled to the first filament 6 and mayeven be being integrally formed with the first filament 6. The secondfilament 6A may form a second concave portion 34A when the containerelement 4 is in the open position. The second concave portion 34A alsomoves the distal opening 20 toward the open position. The first concaveportion 34 and the second concave portion 34A may each extend 90-180degrees when the container element 4 is in the open position and viewedalong the longitudinal axis LA.

Specific aspects of components of the invention are now described andthese aspects, features, and method steps are incorporated into allapplicable embodiments even though not expressly provided as mentionedabove.

The container element 4 may be of any number of constructions. In someembodiments, the container element 4 may be a radially expandableelement, such as a braid, laser cut stent, woven structure, or the like.In other embodiments, the container element 4 may be a non-compliantflexible bag or fabric such as a PET or PTFE materials. In otherembodiments, the container material may be a compliant material such asa polyurethane, silicone, or the like that may stretch and expand asmaterials are pulled into it. In still other embodiments, the containermaterial may be a combination of multiple constructions. For example,the container element 4 may have a bag construction in certain areas anda braid construction in other areas.

In some embodiments the container element 4 is a frame with an attachedmembrane or fabric. The frame may be comprised of a nitinol or stainlesssteel or plastic component that expands radially once delivered out ofthe constraining catheter 8. For example, the frame may be a nitinoltube that is laser cut and shape set to expand when not constrained. Afabric, such as a PTFE graft material or any other membrane material,may be connected to the frame to either provide local flow arrest andcontain the clot once it is within the container element 4 or both. Insome embodiments, the container element 4 may be combination of a braidand a frame element. For example, a small wire braid may extend over aframe structure, possibly on both the inner and outer surfaces of theframe structure.

In some embodiments the container element 4 is a braided wireconstruction. The braid wires may be nitinol, stainless steel, cobaltchromium, plastic, such as PET, or any other suitable material. Thebraid wire may contain radiopaque elements that allow it to bevisualized under fluoroscopy such as a nitinol wire with a platinumcore. Alternatively, the container element 4 may have connected markersthat enable visualization. The number of wires in the braid may bebetween 12 to 128 wires or between 32-64 wires. The braid angle may bebetween 100-200 degrees or between 120-160 degrees. The braid wires maybe between 0.0001″-0.0050″ in diameter or between 0.0005″-0.0020″.Alternatively, the braid wires may be non-circular and may be oval,flat, or rectangular ribbons. The braided geometry may allow thecontainer element 4 to act like a Chinese finger trap where it decreasesin diameter when it is elongated and increases in diameter when it iscompressed. This may provide advantages such as allowing the device 2 toreduce in size when it is pulled out of the body and also secure itselfagainst the vessel 80 when compressive loads are placed on portions ofit such as through the filaments.

In some embodiments, the container element 4 has a predetermined shape46 which is the unrestricted and unbiased shape that it naturally takeswhen no other components are restricting its movement at a giventemperature. The predetermined shape 46 may be different shapes atdifferent temperatures and as used herein shall be defined at normalbody temperature. For instance, the container element 4 may be a braidedconstruction comprised of Nitinol wire. The Nitinol braid may be given apredetermined shape 46 through a shape setting heat treatment where thecontainer element 4 has a defined unrestricted shape. In someembodiments, the container element 4 is configured such that in anunrestricted shape it may expand to close the vessel size. For example,in applications of the middle cerebral artery (MCA), the containerelement 4 may be configured to expand to a diameter between 4 mm and 10mm. Assuming an MCA has an average inner diameter of 4 mm, the containerelement 4 expands until it touches the intimal wall of the vessel 80. Ifthe container element 4 is designed such that it expands to a diameterof 6 mm in air then it may provide a small to moderate amount of radialpressure on the wall of the vessel. By changing the unconstraineddiameter of the container element 4, the amount of radial force exertedon the vessel may be modulated. Additionally, the radial expansion forcemay be adjusted by altering the characteristics of the container element4. For example, if the container element 4 is a braided construction,the following parameters may be changed to increase or decrease thedesire radial force on the vessel: braid angle, number of braided ends,braid material, braid wire diameter, braid wire cross sectional profile,braid coating, etc. The desired radial force may be different fordifferent vessels and different anatomical locations. In someembodiments, the container element 4 has varying diameters orcross-sectional profiles along its length. For instance, theunconstrained diameter may be 8 mm in one or more locations and may be 4mm in one or more locations. In addition, the cross sectional profile ofthe container element 4 may not be generally circular as is shown. Thecross-sectional profile may be ovular, triangular, rectangular, or anyother profile and may vary along the axial length of the containerelement 4. For example, in some locations the profile may be generalelliptical with the semi-major axis in intimal contact with the vessel80 and the semi-minor axis not in contact with the vessel 80. In otherlocations the cross-sectional profile may be circular with the entirecircumference not in contact with the vessel wall. Any number ofdifferent shapes and configurations may be contemplated.

In other embodiments, the container element 4 may not be a fully tubularstructure meaning that container element 4 may represent a rolled-upsurface that may or may not connect to itself. For example, thecontainer element 4 may be comprised of a laser cut pattern on a flatsheet of material that is then rolled to form a substantially circularshape but in which the two rolled edges may or may not connect to eachother.

The container element 4 has a distal opening 20 toward its distal endthat allows for the passing of materials into the container element 4from the distal direction. The distal opening 20 may be configured suchthat in an unrestricted shape it is the same diameter as the sidewall 26of the container element 4. The distal opening 20 defines a distalopening perimeter 64 along the rim of the distal opening 20. In otherembodiments, the distal opening 20 may be larger or smaller than thesidewall 26 of the container element 4 when it is unrestricted such thatthe distal end 16 of the container element 4 tapers outward or inward.If the container element 4 is tapered outward at the distal end 16 ofthe container element 4 it may facilitate the smooth entrance ofmaterials into the container element 4 and reduce the likelihood ofclots from getting dislodged from the components which are retractingthem. If the container element 4 is tapered inward at the distal end 16of the container element 4 it may facilitate the closing of thecontainer element 4 when the filament 6 is tensioned as will bediscussed in more detail below. The distal opening 20 may have across-sectional area which is roughly the same as the cross-sectionalarea of the vessel 80 it is within. For example, in a 5 mm vessel 80 thecross-sectional area of the container element 4 may be between 10-30 mm2or between 18-22 mm2 in a deployed configuration. The size of the distalopening 20 of the container element 4 may defined partially by the shapeand size of the filament perimeter 48 48 as well. For example, thefilament perimeter 48 may be such that it imparts an inward or anoutward radial force on the distal opening 20 of the container element4. In other embodiments, the filament 6 may impart an inward radialforce in some locations and an outward radial force in other locations.In some embodiments, the container element 4 is a flexible bag materialand the filament perimeter 48 fully defines the distal opening 20 sizeand shape.

When fully deployed the container element 4 may have a length of 1 cm-30cm depending on the application. In a MCA application, the containerelement 4 may be between 4 cm-16 cm or 5 cm-10 cm. Standard stentretrievers are 3 cm-5 cm in length. Therefore, if the clot engagementelement is a similar length, in order to fully capture and contain theclot engagement element, the length of the container element 4 may be onthe order of 7 cm. However, as will be shown, the clot engagementelement does not necessarily need to be fully captured by the containerelement 4. In any event, assuming a length of 7 cm of the containerelement 4 when unconstrained, the container element 4 may have a lengthof 14 cm when it is within the constraining element. This is commonlycalled foreshortening where the length of the container element 4increases as it is radially constrained.

The container element 4 may have features which provide partial or fulllocal flow arrest within the vessel such as a coating 108. In theembodiments where the container element 4 is a braid, the coating 108may be a dipped or spayed coating 108 such as silicone. The silicone maybe between 0.0001″-0.0050″ thick or between 0.0005″-0.0010″ thick. Thesilicone can provide a local flow arrest within the vessel 80 bycovering portions of the braid so that blood flow is limited.Additionally, a coating 108 may provide further advantages of keepingthe clot material that is captured by the device 2 better contained. Forexample, the container element 4 may be covered along its entire lengthsuch that when it is deployed within the vessel 80 blood flow stopswithin the vessel 80 as blood cannot pass through the container element4 which is in intimal contact with the vessel 80. In some embodiments,the coating 108 may cover only a portion of the container element 4 suchas the proximal funnel such that the full or partial cross section ofthe vessel is blocking blood flow. In other embodiments the coating 108may be over the entire container element 4. Alternatively, in theembodiments where the container element 4 is a braid, the braid windowsor space between the braid wires may be so small that they provide localflow arrest or reduced flow. For example, if the braid windows are smallenough it may provide local flow arrest without needing to be covered.In some embodiments it may be desirable to allow certain components ofblood to pass through the braid such that the braid acts as a filter tosubstantially reduce blood flow but not fully arrest it.

The container element 4 may include more than one coating 108. In someembodiments, the container element 4 may have a hydrophilic coating 108such as PTFE or other coating material to reduce friction of thecontainer element 4 as it slides within the constraining catheter 8. Thecoatings 108 may be applied to the outer surfaces of the containerelement 4 to facilitate deployment of the container element 4 or may beapplied to the inner surface 52 to facilitate movement of othercomponents such as microcatheter 74 through the lumen of the containerelement 4. In other embodiments, the coating 108 may a drug coating todeliver an active pharmaceutical ingredient (API) to the vessel or localanatomy. This may include drugs such as tissue plasminogen activator(tPa). These may be separate or in addition to a coating 108 thatprovides flow arrest such as a silicone coating. For example, thecontainer element 4 may have a silicone coating 108 which provides flowarrest and additionally have a hydrophilic coating to provide lubricity.

Local flow arrest may advantageously encourage retrograde collateralflow from the vessel such that the clot 78 is at a reduced risk ofdistal embolization since the flow may be reversed. In addition, it mayallow for injection of contrast through a portion of the device 2 suchas through the container element 4 or through the constraining catheter8 which may facilitate identification of the thrombus within the vesselsince there is no flow to carry the contrast away. Alternatively, thedevice 2 may be used to inject therapeutic agents such as tissueplasminogen activator (tPa).

The proximal end 18 of the container element 4 may reduce down to asmall diameter portion 12. In some embodiments, the small diameterportion 12 is defined by a predetermined shape of the container element4. For example, if the container element 4 is constructed of Nitinol theshape set configuration of the container element 4 may include the smalldiameter portion 12 at its proximal end 18. In other embodiments, thesmall diameter portion 12 may not necessarily be defined by apredetermined shape 46 but instead defined by the constraint of theconstraining catheter 8. The small diameter portion 12 may be sized tofit within the inner lumen 24 of the constraining catheter 8. The innerdiameter of the small diameter portion 12 may also be sized to allow forthe passage of catheters and wires within it. Microcatheters 74 whichare used to deploy stent retrievers may be on the order of 0.010″-0.040″outer diameter. Aspiration catheters which are used to grab clotsthrough aspiration may be on the order of 0.020″-0.070″ outer diameter.Therefore, the inner diameter of the small diameter portion 12 may be onthe order of 0.010″-0.080″ or may be on the order of 0.025″-0.060″. Thismay allow other components to pass through the lumen of the containerelement 4 before and after the container element 4 is deployed.

The proximal end 18 of the container element 4 may continue through theconstraining catheter 8 and out of the patient where it can bemanipulated to change its relative position to the constraining catheter8 and filaments. In some embodiments, the proximal end of the containerelement 4 may transition to a catheter or other suitable structure whichis capable of moving the container element 4 forward and backwardaxially or rotationally. The catheter portion of the container element 4may extend from out of the patient and may be manipulated either by theuser, a delivery mechanism, or robotically. The proximal end 18 of thecontainer element 4 may be connected to a vacuum source such thataspiration may be achieved through the lumen of the container element 4.As will be shown in subsequent description, the aspiration may be usedto draw clots into the container element 4 and otherwise prevent distalblood flow.

Returning to FIG. 1 , there is also shown a constraining catheter 8. Theconstraining catheter 8 may be comprised of any number of materials andconstructions which exist in the field of catheters. In some embodimentsthe constraining catheter 8 may be a stainless steel braid reinforcedcatheter with a PTFE inner liner and a Pebax outer jacket. Any number ofother suitable constructions and materials may exist. The constructionand materials of the constraining catheter 8 may vary along its lengthto achieve the desired stiffness and force transmission. In the exampleof a MCA application, the constraining catheter 8 may be ideallydelivered through an intermediate catheter 72 which has been placed inthe cerebral artery. The inner diameter of intermediate catheters 72used in thrombectomy procedures is typically on the order of0.04″-0.08″. Therefore, the outer diameter of the constraining catheter8 may be on the order of 0.04″-0.08″ or 0.05″-0.06″. The inner diameterof the constraining catheter 8 may be sized to allow the passage ofcatheters and wires within it which are delivered distally including thecontainer element 4. Therefore, the inner diameter of the constrainingcatheter 8 may be on the order of 0.010″-0.080″ or may be on the orderof 0.025″-0.060″. The constraining catheter 8 may have a flared orconstricted distal end 16 which facilitates the movement of thecontainer element 4 into and out of the constraining catheter 8. Forexample, the diameter of the distal end 16 of the constraining catheter8 may be flared by 0.001″-0.020″ such that container element 4 is easilyretracted into the constraining catheter 8 by the tapered section.

The constraining catheter 8 may extend out of the patient and can bemanipulated by the user relative to the other components to guide thedevice 2 through the motions described in detail herein. In someembodiments, the constraining catheter 8 may be the same as theintermediate catheter 72 such that there is only one catheter. In someembodiments, the constraining catheter 8 may be connected to a portionof the filament 6 or filaments such that a proximal movement of theconstraining catheter 8 relative to the container element 4 not onlydeploys the container element 4 but may also cause the distal opening 20of the container element 4 to close by way of placing tension on thefilament 6 as the constraining catheter 8 retracts. This will bedescribed in greater detail below.

Returning to FIG. 1 , there is also shown the filament 6. The filament 6has the first arm 28 and the second arm 30 extending through the innerlumen of the container element 4 and connected at the filament perimeter48 toward the distal end 16 of the container element 4. The filament 6may extend through the assembly and out of the patient such that it canbe manipulated by the user, a deployment mechanism, or robotically.Alternatively, the filament 6 may connect to a different componentwithin the device 2 such as the constraining catheter 8 such that themotion of the constraining catheter 8 relative to the container element4 may apply or remove tension from the filament 6. The filament 6 may bea monofilament 6 wire or may be any number of other constructions. Forexample, the filament 6 may be small coil made of any of the materialslisted herein. Alternatively, the filament 6 may be a suture materialsuch as a polypropylene or polyester. The material and construction ofthe filament 6 may vary along the length of the filament 6 and need notnecessarily be the same along its entire length. In some embodiments thematerial is a round wire, whereas in other embodiments the snare may bea coil or a filament 6 of any number of cross-sections such asrectangular, ovular, sheet, or the like. Additionally, thecross-sectional shape and area of the snare filament 6 may vary alongthe length of the snare. In some embodiments, the filament 6 isconstructed of multiple materials. For instance, a portion of thefilament 6 may be flexible like a suture while other portions areelastic like Nitinol. In some embodiments, the filament 6 is a piece ofNitinol wire that is 0.0005″-0.0100″ or 0.001″-0.004″ in diameter.Alternatively, the filament 6 may be stainless steel, tungsten, cobaltchromium, plastic, or any other suitable material. The filament 6 may beshape set to have a predetermined shape such as a circle at the filamentperimeter 48.

Turning now to FIG. 2A-2H, various predetermined shapes 46 of thefilament 6 are shown. This is not intended to be an exhaustive list ofany possible shape but merely to show the variety of shapes which onecould configure the filament 6 to. In FIG. 2A, a filament 6 with a roundfilament perimeter 48 is shown. The filament perimeter 48 may begenerally circular or ovular. The filament perimeter 48 transitions to afirst arm 28 and a second arm 28 through a filament 6 bend. The firstarm 28 and a second arm 28 extend roughly perpendicularly from a planedefined by the filament perimeter 48. As will be shown, the filamentperimeter 48 may be at about the location of the distal opening 20 onthe container element 4 and therefore the filament perimeter 48 maydefine a profile that is roughly the same as the inner surface of thevessel 80. In FIG. 2A, the filament perimeter 48 is about 330-360degrees in circumference such that the first arm 28 and second arm 30are in close proximity. In FIG. 2B, the filament perimeter 48 defines anarc that has an included circumference which is less and may be on theorder of 200-330 degrees such that there is a gap between the filamentbends 54 for the first arm 28 and the second arm 30. In FIG. 2C, thefilament perimeter 48 defines an arc that has an included circumferencewhich is on the order of 360-540 degrees such that there is an overlapof the filament perimeter 48. In FIGS. 2D and 2E, the filament perimeter48 defines a plane that is not substantially perpendicular to thelongitudinal axis of the vessel 80. Filament perimeter 48 is an ovalthat defines a plane which is askew to the central axis of the vessel80. The application of this embodiment will be described in greaterdetail in subsequent figures. In FIG. 2D, the filament bends 54 are at aproximal portion of the filament perimeter 48 and in FIG. 2E thefilament bends 54 are at a distal portion of the filament perimeter 48.In FIG. 2F, the filament perimeter 48 has a nipple 102 feature on itsprofile. The nipple 102 feature may facilitate the closing of the distalopening 20 when the filament 6 is in tension by providing a specificlocation where the filament 6 can bend to a tight radius which may allowthe distal opening 20 to close tightly. In FIG. 2G, the filamentperimeter 48 has an undulating profile 104 that can facilitate theweaving into and out of the container element 4 looped ends 106. In FIG.2H, the filament perimeter 48 defines an arc that has an includedcircumference of 70-200 degrees such that the filament perimeter 48 onlycircumscribes a portion of the distal opening 20. In FIG. 2I, the firstarm 28 and second arm 30 are joined at a filament junction 100 which isclose to the filament perimeter 48. In FIG. 2J, they are joined at afilament junction 100 which is proximally further away from the filamentperimeter 48. In these embodiments, there may only be a single filament6 which extends proximally and therefore needs to be placed in tension.In FIG. 2K, there are two separate filament 6 elements which haveindividual filament perimeters 48. Each of the two filaments has a firstarm 28 and a second arm 30. This embodiment may have less off axisloading of the container element 4 when the filaments 6 are placed intension such that the distal opening 20 may remain generally concentricas it closes. Any number of other filament 6 configurations and shapesmay be contemplated. In some embodiments the filament 6 may only have afirst arm 28 and the filament perimeter 48 may terminate part waythrough the circumference. In such an embodiment, the end of thefilament perimeter 48 may be connected to a part of the containerelement 4. In other embodiments, there may be two or more filaments 6that connect to the distal end 16 of the container element 4. The distalend of each filament 6 may form a hook that is looped around the distaledge of the container element 4 such that there are a series of pullwires which can be activated independently or in conjunction with oneanother to place the distal end 16 of the container element 4 intension. In other embodiments, the filament 6 may have a predeterminedshape 46 that is generally straight wire and which is constrained to oneof the shapes shown in FIG. 2A-2K by the shape of the distal end 16 ofthe container element 4. For example, the filament 6 may be threadedthrough the container element 4 and therefore held in a shape thatresembles one of the shapes shown in FIGS. 2A-2K by nature of beingconnected to the container element 4.

The container element 4 may be connected to the filament 6 in any numberof ways. In some embodiments where the container element 4 is a fabricor bag material, the distal end 16 of the container element 4 may bewrapped around the filament 6 and adhered to itself through the use ofheat sealing or adhesives or any other suitable method. Alternatively,the filament 6 may weave through portions of the container element. Insome embodiments, the container element 4 may include a laser cut stentstructure. The stent may include features such as holes at the distalend which are configured for the filament 6 to weave through. In someembodiments, the container element 4 is a braided structure and thefilament 6 may weave through the braid or looped ends 106 near or at thedistal end 16 of the container element 4. The distal opening perimeter62 and the filament perimeter 48 may be generally the same in someconfigurations such as when the device 2 is deployed and in an openconfiguration. In other configurations such as the constrained or closedconfiguration, the distal opening perimeter 62 and filament perimeter 48are different shapes and lengths.

In FIG. 3 , a detailed view of the distal end 16 of an embodiment of thecontainer element 4 is shown. The container element 4 is constructed ofbraided wires. The wires may double back on themselves as shown byterminating at one end of the container element 4 with looped ends 106.For example, at one end of the container element 4, the braided wiresmay form looped ends 106 by being wrapped around posts duringmanufacturing and then braiding the wires back over the already createdbraid. In this way, the looped ends 106 provide an atraumatic end withinthe vessel and also provide a location where the filament 6 can be woventhrough. The filament perimeter 48 may be woven through these braidedlooped ends 106 so that as the filament 6 is tensioned, it constrictsthe distal opening 20 of the container element 4 like a purse string ordraw string. The filament 6 may weave through back and forth througheach of the looped ends 106 or may weave through every other looped end106 or any weave pattern. For example, the filament 6 may weave throughonly 4 locations of the braided looped ends 106 at 90 degrees apart fromeach other. The weave characteristics may dictate the friction necessaryto open the distal opening 20 of the container element 4 once it isdeployed. It may be advantageous to reduce the friction between thefilament 6 and braid by limiting the number of woven looped ends 106 sothat the radial expansion force of the container element 4 can easilyovercome the friction of the filament 6 expanding as it opens. In someembodiments the filament perimeter 48 can wrap around 360 degrees at thedistal end. In other embodiments the filament 6 can cross over itselfand wrap around between 360 and 720 degrees. In still other embodimentsthe filament 6 may only wrap around 90 to 360 degrees so that only aportion of the distal end 16 of the container element 4 has the filament6 wrapping around. In still other embodiments, the filament 6 is onlyattached to a small section of the container element 4 such as a one ortwo looped ends 106. The filament 6 may also only have a single wirereturning proximally from the distal end 16. The filament 6 may form aloop at the distal end 106 but may connect back to itself such that twofilaments 6 are not required to constrict the distal end 16. Any numberof filaments 6 may be used and connected to the container element 4 andmay be actuated independently or in conjunction.

In some embodiments, the first arm 28 and the second arm 30 may weavethrough sections of the container element 4 along the axial length ofthe container element 4. This may keep the arms 28, 30 constrained tothe sidewall 26 of the container element 4 such that they do not get inthe way of other components which are moving within the containerelement 4. Additionally, keeping the filament 6 constrained to thesidewall 26 of the container element 4 may facilitate the closure of thedistal opening 20 by directing the force applied to the distal opening20 in a radial direction rather than a proximal direction. In otherembodiments, the first arm 28 and the second arm 30 do not weave throughthe side wall 26 of the container element 4 and are left free. In thisembodiment, they may be configured through a predetermined shape 46 toremain biased against the sidewall 26 or may be configured to take anynumber of other shapes.

The container element 4 and filament 6 are configured such that whenthey are deployed the container element 4 is unrestricted and thefilament 6 is not under a significant amount of proximal tension. Inthis condition, the distal opening 20 of the container element 4 is openand positioned to receive clot 78 material from the distal direction.The distal opening perimeter and filament perimeter 48 may be generallythe same shape and length in this position. When tension is then appliedto the filament 6, the filament perimeter 48 and distal opening 20 maybegin to move proximally. The distal opening 20 is configured toconstrict and close as additional tension is applied to the filament 6.In this manner, the closure of the distal opening 20 is actuated by thetension applied to the filament 6. The distal opening perimeter P mayreduce in length as the looped ends of the braid get closer togetherwhile the filament perimeter 48 is the same fixed length. However, theamount of the filament perimeter 48 that the distal opening perimeter 62occupies is less. For example, in the deployed configuration the distalopening perimeter 62 may overlap with about 60% to 100% or 80% to 100%of the filament perimeter 48. In the closed configuration, the distalopening perimeter 62 may overlap with about 1% to 30% or 5% to 15% ofthe filament perimeter 48. The filament perimeter 48 has remained thesame fixed length but its shape has changed and only a portion of it hasthe distal opening perimeter 62 overlapping.

In some embodiments the opening of the distal opening 20 may be actuatedby the removal of tension from the filament 6. As tension is removed,the filament 6 may return to its predetermined shape 46 and likewise thecontainer element 4 may return to its unrestricted predetermined shape.As such the distal opening 20 may return to an open position. In otherembodiments, once the distal opening 20 is closed by means of applyingtension to the filament 6, the distal opening 20 will not open uponrelease of the tension to the filament 6. In this manner the device 2locks into a generally closed distal opening 20 once tension is appliedand even the removal of the tension does not allow the distal opening 20to open.

In other embodiments the filament perimeter 48 may be locatedsubstantially away from the distal end 16 of the container element 4.For instance, rather than weaving the filament 6 through the looped endsof the braid the filament 6 may be woven through any section of thecontainer element 4 along its axial length. In some embodiments, thefilament perimeter 48 may not necessarily be woven through any featureon the container element 4. For example, the filament perimeter 48 mayexist primarily on the outer surface of the container element 4 and maysimply pinch the outside of the braid at a given location along theaxial length of the container element 4 instead of constricting it likea purse string. In such an embodiment, the first arm 28 and second arm28 may still enter the inner lumen of the container element 4 bythreading through a portion of the container element 4. The distalopening 20 and distal opening perimeter 62 may be defined by thelocation of the filament perimeter 48 or may be defined by the distalend 16 of the device 2.

While filament 6 is generally described herein as a snare type mechanismthat cinches the distal opening 20 of the container element 4, any othertypes and closures mechanisms may be contemplated. For example, thecontainer element 4 may contain one or more flaps 88 at its distal endthat are connected to one or more filaments. The one or more flaps 88may be folded inward by tensioning the filaments so that the flapscollapse and restrict the distal opening 20. In other embodiments,twisting mechanisms may be used to constrict the distal opening 20 ofthe container element 4. For example, the distal end 16 of the containerelement 4 may be held generally stationary while the body of thecontainer element 4 is twisted clockwise. In this manner the distal end16 of the container element 4 may constrict and close the distal opening20. Any number of other closure mechanisms may be contemplated.

Turning now to FIG. 4A-4P, a first embodiment of the device 2 is shown.In FIG. 4A, an intermediate catheter 72 is shown within a vessel whichcontains a clot. The intermediate catheter 72 may be any standard sizesuch as between 0.010″ to 0.500″ OD or between 0.050″ and 0.110″ outerdiameter depending on the anatomical location it will be used. It may becomprised of any typical materials used for such catheters, such asPebax, polyimide, PEEK, multi-layer braided composite, or any othersuitable material or composition. The vessel shown may be a cerebralartery such as the middle cerebral artery (MCA) or any other vesselwithin the body of a human or animal. The size of the intermediatecatheter 72 may depend on the size of the vessel 80 and the expandedsize of the container element 4 as will be shown. Larger vessels 80often will require larger catheter sizes while smaller vessels 80 oftenwill require smaller catheter sizes. The intermediate catheter 72 isplaced proximal of the clot 78 and in a position to deploy other partsof the invented device 2.

In FIG. 4B, a microcatheter 74 has traversed the clot 78. Themicrocatheter 74 may be any suitable size such as 0.010″ to 0.080″.Prior to traversing the clot 78 with the microcatheter 74, a guidewireor other such element may be included and used to guide themicrocatheter 74 across the clot. In some embodiments a guidewire may berequired while in other embodiments a guidewire is not necessary. If aguidewire is used, it will often be withdrawn once the microcatheter 74traverses the clot and the clot engagement element may then be insertedinto the microcatheter 74 while it is traversing the clot. This placesthe clot engagement element 58 across the clot 78 so that it is in anoptimal location when the microcatheter 74 is withdrawn.

In FIG. 4C, the microcatheter 74 is withdrawn and a clot engagementelement 58 is left behind and engages with the clot. The clot engagementelement 58 may be a stent retriever type design as shown but it may alsobe any other element suitable for pulling a clot proximally. In theembodiment shown, the clot engagement element 58 has a series of strutsor interwoven elements that expand radially outward when it is notconstrained which allow it to engage with the clot 78 and pull itproximally when the clot engagement element 58 is retracted. In otherembodiments, the clot engagement element 58 is a balloon that isinflated distally to the clot 78 such that as it retracts, it pulls theclot 78 proximally with it. In still other embodiments, the clotengagement element 58 is a Nitinol wire with a convoluted shape suchthat when it is deployed it likewise engages with the clot 78 andsecures itself in different areas of the clot. Any number of other clotengagement elements 58 may be contemplated.

In FIG. 4D, the intermediate catheter 72 is withdrawn, exposing aconstraining catheter 8 which constrains the container element 4. Insome embodiments there is no need for a constraining catheter 8 and theintermediate catheter 72 can constrain the container element 4 such thatwhen it is retracted, as will be shown with the constraining catheter 8,the container element 4 is deployed. In some embodiments, theconstraining catheter 8 with the container element 4 is within theintermediate catheter 72 during the navigation and delivery of themicrocatheter 74 while in other embodiments it is advanced into positionwithin the intermediate catheter 72 at some point between navigation andafter the clot engagement element 58 has been deployed.

In FIGS. 4E-4H show a container element 4 being deployed within thevessel. In FIG. 4E, the constraining catheter 8 begins to be retractedand the distal end 16 of the container element 4 is deployed. Theinitial deployment steps of the filament perimeter 48 and distal end 16of the container element 4 will be shown in greater detail in FIGS.7A-7G.

In the embodiment shown in FIGS. 4E-4H, the container element 4 has arelatively consistent unconstrained diameter of 3 mm-6 mm and is sizedsuch that when deployed within an MCA, it is uniformly in contact withthe vessel wall. In FIG. 4E, the container element 4 is partiallydeployed and a filament perimeter 48 exists at the distal end 16 of thecontainer element 4. The plane formed by the filament perimeter 48 isgenerally perpendicular to the longitudinal axis of the vessel 80.

In FIG. 4F, the container element 4 is more deployed out of theconstraining catheter 8. As is shown, when the container element 4 comesout of the constraining catheter 8 it self-expands against the vessel80. In other embodiments, the container element 4 may be activelyexpanded with the use of balloons, shape memory materials such asnitinol that transition at a given applied temperature, or any othermeans. For example, in some embodiments the constraining catheter 8 maybe fully retracted before the container element 4 is actively expandedin the vessel. The filament perimeter 48 comes out of the constrainingcatheter 8 and automatically expands to the vessel 80 with the containerelement 4 open. In some embodiments the filament perimeter 48 may comeout of the constraining catheter 8 in a fully or partially closedconfiguration and then may be opened once in place.

In FIG. 4G, the container element 4 is more deployed as the constrainingcatheter 8 is further retracted. In some embodiments, the constrainingcatheter 8 is retracted to deploy the container element 4. In otherembodiments, the container element 4 may be advanced out of theconstraining catheter 8. In still other embodiments there may be acombination of retracting the constraining catheter 8 and advancing thecontainer element 4. In fact, as shown the axial length of the containerelement 4 is significantly longer when it is within the constrainingcatheter 8. Therefore, as the container element 4 is deployed byretracting the constraining catheter 8, the proximal end of thecontainer element 4 must be advanced if the distal end of the distal end16 of the container element 4 is to stay in a fixed location. Since thecontainer element 4 may be in contact with the vessel 80 when it isdeployed it may be advantageous to keep any areas which are contactingthe vessel 80 stationary so as not to injure the vessel 80. Therefore, aretraction of the constraining catheter 8 may be accompanied by anadvancing of the proximal end 18 of the container element 4.

In FIG. 4H, the container element 4 is shown in a fully deployed state.The constraining catheter 8 has been retracted far enough that aproximal funnel area 14 of the container element 4 is exposed. Theproximal funnel area 14 may be a predetermined shape that the containerelement 4 has at the proximal end 18 of its vessel diameter portion 10.The proximal funnel area 14 tapers the vessel diameter portion 10 to thesmaller diameter portion 12 that fits within the constraining catheter8. It should be noted that a proximal funnel area 14 may not be requiredsince the container element 4 may naturally come out of the constrainingcatheter 8 in a funnel shape as it is being deployed. As will bediscussed the proximal funnel area 14 may provide local flow arrest inthe vessel 80. In some embodiments, the user may select the length ofthe container element 4 to deploy. For example, in the case of capturingsmall clots only ¼-½ of the vessel diameter portion 10 of the containerelement 4 may be deployed. Other times in the case of longer clots 78,the full length of the vessel diameter portion 10 may be deployed. Theamount of container element 4 may be selectable by the user.

As shown in FIG. 4H, the microcatheter 74 may remain within the device 2or it may be removed from the patient at any point during the procedure.In some embodiments, the microcatheter 74 is a mono-rail catheter thatallows it to be removed while keeping the clot engagement element inplace. In other embodiments, the microcatheter 74 remains in place andmay be used in subsequent steps to sheath the clot engagement element 58once the clot is captured within the container element 4.

In FIG. 4I the clot engagement element 58 with the clot 78 is withdrawntoward the distal opening 20 of the container element 4. As the clotengagement element 58 reaches the distal opening 20 of the containerelement 4 it enters the container element 4. The distal end 16 of thecontainer element 4 may be flared outward, either by its predeterminedshape or by a radial force from the filament perimeter 48, so that theclot engagement element 58 enters smoothly and does not get stuck on anypart of the container element 4 as it enters. Alternatively, the distalend 16 of the container element 4 may be constricted partially.

In FIG. 4J, the clot engagement element 58 has been withdrawn so that itis entirely within the container element 4. Some embodiments of the clotengagement element 58 may leave components outside of the containerelement 4. One critical aspect is that most or all of the clot 78 thatwill be withdrawn from the patient is within the container element 4even though pieces of the clot engagement element 58 may remain outsideof the container element 4. For example, the clot engagement element 58may be a balloon that pulls the clot 78 into the container element 4 butitself does not go fully within the container element 4. In someembodiments, portions of the clot engagement element 58, guidewire,microcatheter 74, or any other structure may remain distal to the distalopening 20. In this manner, when the distal opening 20 is fully ormostly closed, devices may be navigated beyond the distal end of thedistal opening. For example, after retracting a clot engagement element58 with a clot 78 into the container element 4, the distal opening 20may be disclosed as described herein but with a portion of the clotengagement element 58 remaining distal. The user may then use amicrocatheter 74 to constrict the clot engagement element 58 again andadvance the microcatheter beyond the distal opening 20. In this manner,a clot engagement element 58 may be used again to engage with additionalpieces of clot 78 which were not retracted the first time. Such anembodiment can be used when the clot engagement element 58 is a stentretriever or an aspiration catheter 76. The distal opening 20 can beopened by releasing tension on the filament 6 and the additional clot 78material can be retracted within the containing element 4. This processmay be repeated as many times as necessary and may be useful in removingsignificant amounts of clot 78 or in instances where only fragments ofthe clot 78 can be engaged.

In FIGS. 5A-5E, the distal end 16 of the container element 4 andfilament perimeter 48 are shown in greater detail during the closure ofthe distal opening 20. In FIG. 5E, the container element 4 is shown withthe distal opening 20 in the open configuration where the clotengagement element 58 can be withdrawing into the container element 4.

In FIG. 4K, the distal opening 20 of the container element 4 begins toclose. In the embodiment shown, a proximal tension is applied to thefirst arm 28 or second arm 30 or both. The tension can be equal acrossthe arms 28, 30 or can be different. In some embodiments only the firstarm 28 is tensioned while in other embodiments both arms are tensioned.The tension in the filament 6 imparts a proximally directed force on thedistal end 16 of the container element 4. This may be translated into acompressive load on the container element 4. During the proximal loadingof the filament 6, the filament perimeter 48 begins to move proximallyand change shapes. Additionally, the distal end 16 of the containerelement 4 and distal opening 20 begin to move proximally as a result ofthe proximal force applied through the filaments 6. The braidedstructure may be designed to increase in diameter when it is constrictedand decrease in diameter when it is lengthened. In the embodiments wherethe container element 4 is of a woven or braided construction, as thedistal end 16 of the container element 4 moves proximally it may expandradially. At some point the radially expansion may be constrained by thevessel 80 and the container element 4 may then impart a radially outwardforce on the vessel 80. In some embodiments where the container element4 is already in close approximation with the vessel 80 the containerelement 4 may not substantially expand when it is placed under acompressive load but rather may directly impart a radially outwardforce. In some embodiments only a portion of the container element 4such as the distal end 16 may expand radially and impart a radiallyoutward force while in other embodiments a substantial amount of thecontainer element 4 may do so. The outward force may facilitate insecuring at least a portion of the container element 4 to the vessel 80and prevent it from moving proximally. In this manner, the tensionapplied to the filament 6 may secure the container element 4 distally tothe vessel 80 such that the distal opening 20 can be closed. If thecontainer element 4 is not constrained and secured by the vessel 80,there must be a component or components which impart a reaction force tosupport the distal end while the distal opening 20 is closing. In someembodiments this may be the container element 4 itself which may havestructures and frames to support a compressive load. This may be true inthe case of a framed configuration of the container element 4.Alternatively, additional catheters or support structures may provide areaction force to hold the distal end while the distal opening 20 isclosed. In some embodiment which will be shown in greater detail below,the filament 6 may be supported by a filament catheter 82 which canprovide such a function. An advantage of the braided structure of thecontainer element 4 described herein is that the device 2 can be veryflexible and no stiff or rigid components are required because it issecured to the vessel 80 itself and only when tension is applied to thefilament 6.

In FIG. 5B, a closer view of the distal end 16 is shown with thefilament perimeter 48 beginning to constrict the distal opening 20. Ascan be seen, the filament perimeter 48 remains a fixed length is movingproximally such that the distal opening perimeter 62 is decreasing inlength. The looped ends 106 of the braid are being constricted like apurse string with a pull wire. The distal opening perimeter 62 isoccupying a smaller portion of the filament perimeter 48 as more tensionis applied.

In FIGS. 4L and 5C, additional tension is applied to the filament 6 andthe distal opening 20 is constricted further. The distal end 16 of thecontainer element 4 and the filament perimeter 48 have moved furtherproximally. In FIGS. 4M and 5D, the filament perimeter 48 and distalopening 20 have moved further proximally such that they are within thesidewall 26 of the container element 4. The distal opening perimeter 62now occupies a small portion of the original filament perimeter 48 atits very distal end. The container element 4 has inverted as thefilament perimeter 48 moves proximally and a portion of the containerelement 4 is secured by the vessel 80. In FIGS. 4N and 5E, the filamentperimeter 48 and distal opening 20 have moved even further proximally.The filament perimeter 48 has changed shapes from the predeterminedshape 46 to an elongated loop due to the tension across the elements. Insome embodiments, the distal opening 20 is generally concentric with thevessel 80 while in other embodiments the distal opening 20 may be ofaxis or angled in any manner determined by the applied forces.

The cross sectional area of the distal opening when it is in the closedconfiguration may be between 0-1.0 mm2 or between 0.01-0.2 mm2. Thedistal opening 20 must be mostly closed to prevent any parts of the clot78 from coming out of the container element 4. The distal opening 20 isformed by the space between the looped ends 106 of the braided containerelement 4. In the closed configuration, the looped ends 106 are bunchedup close together such that the effective distal opening perimeter 62 ofthe distal opening 20 is significantly reduced from the open shape. Forexample, if the device 2 is used in a cerebral artery application anddeployed into a vessel with a 5 mm diameter, the circumference of thedistal opening 20 when the container element 4 is deployed may bebetween 10 mm-20 mm or between 14 mm-17 mm. When the distal opening 20is transitioned to a closed configuration, the circumference may bebetween 0.01 mm-5 mm or between 0.5 mm-2 mm. The distal openingperimeter 62 is now only occupied by part of the filament perimeter 48which has been tensioned and so the majority of the filament perimeter48 is now proximal to the distal opening 20. The shape of the distalopening 20 configuration in this shape is not necessarily circular andin fact is likely not circular. The shape may be like a horseshoe orhalf-moon or any portion of an arc or bent wire.

In FIG. 5E, the distal end 16 of the container element 4 is showninverted such that it has move further proximally within the containerelement 4 itself. The tension in the filament 6 has pulled the distalend 16 proximally and secured the distal opening 20 closed.

In some embodiments the filaments 6 are connected to the constrainingcatheter 8 such that the constraining catheter 8 can be furtherretracted and the filaments 6 can close at the distal end 16. In such anembodiment, the user only needs to retract one component, in this casethe constraining catheter 8, in order to deploy the container element 4and then continue to retract it in order for the distal opening 20 toconstrict. FIGS. 4J-4N show the constraining catheter 8 movingproximally as the filament 6 is placed in tension indicating such aconfiguration. This may provide advantages for the user interface andsimplicity of the device 2. In some embodiments, the clot engagementelement 58 or the intermediate catheter 72 may be connected similarly tothe filament 6 to perform a similar function as described above. Inother embodiments, a handpiece may exist outside of the body whichhandles the relative movements of the catheters and elements. Forexample, a syringe type motion or a trigger type motion by the user maycause the device 2 to go through its relative motions as describedherein. In this manner the user does not have to think about whichcomponent to move but rather can just activate a simple interface tomove through the various stages.

In FIG. 4O, the clot engagement element 58 has been removed from thebody leaving the majority of the clot 78 behind in the container element4. In some embodiments this step is not performed and the clotengagement element 58 can remain in position relatively to the containerelement 4 as the entire device 2 is removed from the body.

In FIG. 4P, the device 2 begins to be removed from the body by pullingit proximally. In the embodiment shown, the container element 4 is abraid that decreases in diameter as it is placed under tension. Thecontainer element 4 therefore stretches as shown and can be furtherpulled into other catheters if necessary. At this point the clot 78 isfully contained within the container element 4 and will not distallyembolize as it is retracted. The container element 4 and device 2 may bestretched as much as necessary to remove it from the body. In someembodiments, once the filament 6 is pulled taut and the distal opening20 of the container element 4 is constricted, it does not significantlyopen again even if the tension in the filament 6 is reduced or removed.This may be caused by a locking mechanism in the device 2 that locks thefilament perimeter 48 closed or may be simply due to friction within thesystem that prevents the filament perimeter 48 from opening once it isclosed. Alternatively, the distal opening 20 of the container element 4may automatically open once the filament 6 is relaxed. In someembodiments, after the device 2 is removed from the body it may beopened and the device 2 may be used again for additional clots 78 andforeign bodies.

In FIGS. 6A-6H, an alternative embodiment of the device 2 is shown. Inthis embodiment, the clot engagement element 58 is an aspirationcatheter 76 rather than a stent retriever. In FIG. 6A, the containerelement 4 has been deployed in the vessel but no microcatheter 74 orstent retriever necessarily traverse the clot. Instead, an aspirationcatheter 76 exists within the lumen of the device 2 and may be advanced.The aspiration catheter 76 may be comprised of any of the materials orconstructions known to one skilled in the art of catheters. The outerdiameter may be on the order of 0.02″ to 0.080″ and sized to fit withinthe lumen of the container element 4. The aspiration catheter 76 may beconnected to a vacuum source external or internal to the patient thatprovides suction to the distal end of the aspiration catheter 76. Theaspiration catheter 76 can be used for aspirating blood such that itflows in a proximal or retrograde manner within the cerebral artery.Additionally, the suction in the aspiration catheter 76 can be used toengage and remove clots 78 or foreign bodies.

In FIG. 6B, the aspiration catheter 76 is advanced distally toward theclot 78. In FIG. 6C, suction applied to the clot 78 may pull the clot 78toward the aspiration catheter 76 or alternatively the aspirationcatheter 76 may be advanced all the way to the clot 78 before suction isapplied. In FIG. 6D, the aspiration catheter 76 is withdrawn into thecontainer element 4 with the clot 78 such that the clot 78 is containedwithin the container element 4. In some embodiments, the clot 78 may bein multiple pieces or may break apart during the aspiration andretraction. In such cases, the aspiration catheter 76 may be extendeddistally multiple times from the container element 4 and engage with newpieces of clot 78. The clot 78 can be retracted into the containerelement 4 and can then be dislodge from the aspiration catheter 76 byreleasing the suction or providing a positive pressure through theaspiration catheter 76 to dislodge the clot 78. Alternatively, thedistal opening 20 of the container element 4 can be partially closed asdescribed herein and used as a method of keeping the clot 78 within thecontainer element 4 while allowing the aspiration catheter 76 to bedistally extended again to engage with another piece of clot 78.

In FIG. 6E, the filament 6 is tensioned and the distal opening 20 beginsto close and may retract proximally. In FIG. 6F, the filament 6 isfurther tensioned and the distal opening 20 closes further. In thisstate, the aspiration catheter 76 could be advanced distally to extendout of the container element 4 and engage with another clot 76. In suchembodiments, a guidewire or microcatheter 74 may be left distal to thedistal opening 20 so that the aspiration catheter 76 can traversethrough the distal opening 20. Before pulling the new clot 78 into thecontainer element 4, the distal opening 20 may be opened as needed byreleasing tension on the filament 6. Aspiration may be applied throughthe container element 4 to keep any loose clot fragments within thecontainer element 4 while the distal opening 20 is partially or fullyopen. In FIG. 6G, the distal opening 20 is inverted within the containerelement 4. In FIG. 6H, the distal opening 20 is further inverted andmoved proximally along with the filament perimeter 48.

In some embodiments, a separate aspiration catheter 76 is not necessary.The aspiration can be applied to the lumen of the container element 4such that flow is directed in from the distal opening 20. The containerelement 4 can be positioned just proximal to the clot 78 so that whenaspiration is applied, the clot 78 is suctioned into the containerelement 4. In any of the embodiments described herein aspiration may beapplied to any of the elements. For example, a vacuum source may befluidly connected to the constraining catheter 8, container element 4,microcatheter 74, aspiration catheter, intermediate catheter 72, or anyother component.

Turning now to FIG. 7A-7G, an embodiment of the device 2 is shown withthe container element 4 deploying out of a constraining catheter 8 ingreater detail. In FIG. 7A, a constraining catheter 8 is shown with adistal end. As mentioned, the constraining catheter 8 may be a separatecatheter or may be an intermediate catheter 72 or any other catheterwithin the device 2. In FIG. 7B, the container element 4 begins todeploy. A first leading portion 38 of the filament(s) 6 begins to exitthe constraining catheter 8 as shown in a ‘bunny ears’ configuration.The term bunny ears is intended to describe the shape shown in FIG.7B-7D, however this term should not be limiting to other shapes orconfigurations which may accomplish the same thing. In FIG. 7C, thefirst leading portion 38 of the filament 6 exit the constrainingcatheter 8 more and begin to fold outward. The first leading portion 38forms a first loop 40 that resembles a bunny ear. A second leadingportion 42 may also exist and move with the first leading portion 38. InFIG. 7D, the braid of the container element 4 begins to deploy as shown.As the distal end 16 of the container element 4 begins to open slightly,the length of the filament 6 within the first loop 40 begins to becomethe filament perimeter 48 at the distal end. In FIG. 7E, the containerelement 4 is further deployed and the distal end has opened upsubstantially from its constrained shape within the constrainingcatheter 8. At this point, most of the length of the filaments 6 thatwas previously within the ‘bunny ears’ shape has become the filamentperimeter 48 of wire at the distal end 16 of the container element 4.There is no significant excess filament 6 length at the distal end 16 ofthe container element 4 and the distal end 16 of the container element 4has been deployed in a primarily open configuration, not a constrictedconfiguration. In FIG. 7F, the container element 4 is further deployed.

In FIG. 7G, the container element 4 is mostly deployed. The filamentperimeter 48 at the distal end 16 of the container element 4 is in theopen configuration and the arms 28, 30 run on the inside surface of thecontainer element 4 and into the constraining catheter 8. At this point,the clot engagement element 58 could be pulled into the containerelement 4 at the distal end 16.

The ‘bunny ears’ shape of the filaments may be important because it isone embodiment in which the container element 4 may be deployed with anopen distal end 16. As used herein, ‘bunny ears’ refers to a specificaspect of the leading portion 38 and all combinations and features shallbe shared without indispensable features from either. That is, allfeatures of the ‘bunny ears’ needn't include a closed loop 50 nor morethan one for those features to be used with any aspect of the leadingportion 38 independently. Stated another way, the terms may beinterchangeable without impugning any necessity of one or the other orany feature of one to the other by necessity. When the container element4 is within the constraining catheter 8, the distal opening 20 is muchsmaller than when it is open after being deployed. For example, when itis within the constraining catheter 8, the distal opening 20 may be 1.0mm in diameter versus when it is deployed and open it may be 5.0 mm indiameter. In this example, this represents a 5× increase in diameter andcircumference. Therefore, since the filament perimeter 48 extends aroundthe circumference of the container element 4, the length of the filament6 at the distal end 16 has to similarly increase by 5×. In someembodiments, the filament 6 at the distal end 16 can simply grow inlength by pulling more filament 6 distally. However, the force requiredto pull more filament 6 distally may be significant compared to theopening force of the container element 4. For example, if the containerelement 4 is a shape set braid that has a nominal 5 mm diameter then itwill have a given radial force trying to open the distal end once it isdeployed from a 1 mm constraining catheter 8. However, this force maynot be enough to pull more filament 6 distally especially if the device2 is long or curved due to anatomical constraints. Therefore, the distalend 16 may not open fully when it is deployed unless anotherconsideration is given for the increase in filament 6 length at thedistal end. The ‘bunny ears’ keep an amount of excess filament length atthe distal end 16 of the container element 4. Therefore, when thecontainer element 4 is deployed, the filament perimeter 48 at the distalend 16 can form an open circular shape. This is particularly relevant inembodiments where the filament 6 is shape set to a predetermined shape46 such as a circle. The 90 degree filament bend 54 where the filament 6transitions from the filament perimeter 48 to the arms 28, 30 going backalong the longitudinal length of the device 2 does not movesubstantially relative to the container element 4 when the device 2 isdeployed versus when it is constrained. The length of the filamentperimeter 48 instead transforms into the ‘bunny ears’ shape and is thenconstrained by the constraining catheter 8 with leading portions 38extending distally from the end of the container element 4. In someembodiments the shape set profile of the filament 6 perimeter caninclude features which encourage the ‘bunny ears’ shape or a similarshape. For example, the filament perimeter 48 may be primarily a circlebut may additionally have small nipples 102 extending radially outwarddefined by the loop pathway as shown in FIGS. 2F and 2G. This mayprovide a specific place for the ‘bunny ears’ to bend when they areconstrained within the constraining catheter 8. Though FIGS. 7A-7G showa ‘bunny ears’ shape, any number of other shapes may be contemplatedsuch as a single loop, several loops, or any other shape that takes upthe filament length when it is constrained.

In other embodiments, the excess amount of filament 6 length is foldedor bunched up in any number of other locations. In FIGS. 14A-14C, anembodiment of such a device 2 is shown. In FIG. 14A, a container element4 is shown in a constrained configuration. Although a constrainingcatheter 8 is not shown, it can be appreciated that the containerelement 4 is radially constrained within a catheter. As shown the distalopening 20 of the container element 4 is relatively small. There is afilament 6 with a filament junction 100 as also described in FIGS. 2Iand 2J, such that there is a single arm 28 extending proximally from thefilament perimeter 48. The filament perimeter 48 has a generallycircular predetermined shape 46 when unconstrained but in theconstrained configuration shown the filament perimeter 48 has anelongated loop shape. The filament perimeter 48 extends along a givenlength of the longitudinal axis LA of the container element 4 that isroughly one half of the circumference of the filament perimeter 48 whenit is unconstrained. For example, if the diameter of the filamentperimeter 48 is 5 mm, the longitudinal length of the filament perimeter48 when stretched as shown may be about 6 mm-9 mm. The distal arm 98transitions to a region of filament excess length 96 which is foldedinto the constraining catheter 8 and then transitions to a filamentproximal arm 94. As will be shown, the filament excess length 96 isfolded and stored within the constraining catheter 8 so that when thefilament perimeter 48 expands to its unconstrained shape, the filamentexcess length 96 can be utilized. In FIG. 2B, the container element 4and filament perimeter 48 have been deployed out of the constrainingcatheter 8. The filament perimeter 48 now extends a very short length ofthe longitudinal axis LA of the container element 4. For example, thefilament perimeter 48 may extend only about 0 mm-3 mm or 0.25 mm-1 mm.As a result, the filament junction 100 advances distally by about thedifference between the longitudinal length of the filament perimeter 48in the constrained shape and the longitudinal length of the filament 6in the deployed shape. For example, this might be about 1 mm-9 mm or 3mm-6 mm. The filament excess length 96 may then unfold and allows theextension of the filament distal arm 98 without substantial movement ofthe filament proximal arm 94. The folded filament excess length 96enables the frictional force of pulling the filament distal arm 98 to beminimized since the filament proximal arm 94, which extends throughadditional components and potentially tight turns, does not need to movesubstantially. Therefore, the radial opening forces of the filament 6 orthe container element 4, or both, do not need to overcome a largefrictional force and may still achieve their open deployed position. Thefolded filament excess length 96 may exist at any location within any ofthe catheters but may be optimally applied within the container element4 and more optimally toward the distal end 16 of the container element 4and as explained elsewhere herein. The features related to the workinglength WL may be combined in any subset of features as being relatedaspects of the invention and all such combinations and sub-combinationsare expressly provided as further aspects of the present invention. Forexample, it is expressly provided even though not explicitly stated thatthe folded filament 6 is positioned within 10 mm of the distal end sothat all features describe above concerning the working length areequally applicable to the folded filament 6. As another example, FIG. 14shows that the excess length may be along the distal portion and formedby a first fold and a second fold forming a flat z-shaped portion forthe filament excess length 96. In FIG. 14C, the device 2 is shown in aclosed configuration as the proximal arm 28 is placed in tension. Thefilament excess length 96 may unbend more than is shown in the figure,but it should be noted that the shape of the filament 6 in the closedconfiguration is unique and different from the shape of the filament 6in the constrained position.

In some embodiments, the filament perimeter 48 shape when the containerelement 4 is in the constraining catheter 8 is different than the shapeof the filament perimeter 48 when the distal opening 20 is closed. Thefilament perimeter 48 therefore goes through at least 3 unique shapes.First, when the container element 4 is in the constraining catheter 8,the filament perimeter 48 is in a shape that may look like the ‘bunnyears’ or any other shape where the filament excess length 96 isaccounted for. This includes the askew plane configuration described ingreater detail below. Second, when the container element 4 is in theopen deployed configuration, the filament perimeter 48 forms acircumference of the distal opening 20 that is generally circular. Thefilament perimeter 48 may be at or close to its predetermined shape 46at this point. Third, when the filament 6 is in tension and the distalopening 20 is closed, the filament perimeter 48 resembles an elongatedloop or stretched rubber band where the distal end of the filamentperimeter 48 forms a small circumference of the distal opening 20 whichmay or may not be circular. The filament perimeter 48 transitionsbetween these three shapes during the normal use of the device 2.Specifically, the first and third shapes are unique meaning that theshape of the filament perimeter 48 when the container element 4 is inthe constraining catheter 8 is not necessarily the same as when thedistal opening 20 is closed.

In FIGS. 8A and 8B, another embodiment which accounts for the diameterchange is shown. In some embodiments other designs which address thefilament length issue may be utilized. The filament perimeter 48generally forms a plane. The plane may be a perpendicular plane 66 whichis perpendicular to the longitudinal axis LA of the container element 4as shown in FIGS. 4A-4P, or the plane may be askew to the longitudinalaxis LA. In FIG. 8B, the plane is tilted by an askew angle 64 of about30 degrees from the perpendicular plan 66. The filament perimeter 48forms an ellipse or similar shape and has a distal section at one apogeeand a proximal section at the other apogee. An advantage to this designis that when the container element 4 is constrained within theconstraining catheter 8, as shown in FIG. 8A, it increases in length.Therefore, if the filament perimeter 48 is askew, it will increase inlength as it is constrained radially and the amount that it is askewwill increase. So the filament excess length 96 is transformed from alarger diameter when it is deployed to a longer length when it isconstrained. This addresses the same problem identified above such thatthe filaments 6 do not need to move distally so that the distal end 16of the container element 4 can open once it is deployed. The excessfilament length needed to change from a constrained shape to a deployedshape is already in place at the distal end and the arms 28, 30 do notneed to be pulled distally a substantial amount. Additionally, having anaskew distal end opening may provide advantages for guiding the clotengaging element 58 into the container element 4. In some embodimentsthe distal end 16 of the container element 4 with its crown of loopedends is also askew to its longitudinal axis LA while in otherembodiments the filament perimeter 48 is simply threaded through thebraid of the container element 4 at an angle while the distal end isstill perpendicular to the longitudinal axis LA. The amount that thesnare is askew to the perpendicular plane 66 may be between 2-60 degreesor between 10-30 degrees. When the embodiment shown in FIGS. 8A and 8Bis in the closed configuration by placing tension on one or both of thearms 28, 30, the closed shape may look similar to other embodimentsshown and described herein. Meaning, the shape of the filament perimeter48 in the closed configuration is not necessarily the same as the shapeof the filament perimeter 48 in the constrained configuration.

In some embodiments, the filament perimeter 48 does not define a singleplane and instead may be a more complex three-dimensional shape. Forexample, the filament perimeter 48 may have portions that are askew tothe longitudinal axis LA of the container element 4 and other portionsthat are askew in a different angle or orientation. The filamentperimeter 48 may have protrusions that extend proximally or distally.The filament perimeter 48 is not constrained by a single plane.

In FIGS. 9A-9F, the closure of the distal opening 20 of the containerelement 4 is shown in greater detail. The container element 4 is withina 5 mm vessel. In these figures, the clot 78 and clot engagementelements 58 are not shown but would be within the container element 4during this step. In FIG. 9A, the distal end 16 of the container element4 is generally open such that it could receive the clot engagementelement 58 to be pulled into the container element 4. The filamentperimeter 48 is in an open shape and there may be little or no tensionin the arms 28, 30. Once the clot 78 and clot engagement elements 58 arewithin the container element 4, tension can be placed on the arms 28, 30as shown in FIG. 9B which moves the distal end 16 of the containerelement 4 proximally as the braid bunches up and expands radially. Thedistal opening 20 of the container element 4 effectively closes as thefilament 6 is pulled proximally. As can be seen in FIG. 9C, the shapeset profile of the circular filament perimeter 48 is retracted furtherand stretched so that only a small amount of the filament perimeter 48remains at the distal opening 20 as it is closed and the distal openingperimeter 62 is significantly reduced.

In FIG. 9D, the filaments arms 28, 30 are pulled further proximally andthe distal opening 20 of the container element 4 moves proximally aswell and even folds back within itself. In FIG. 9E, the distal end 16 isfolded back even further. This may be required in some embodiments whilein other embodiments less tension is required on the arms 28, 30. Acritical aspect is that the clot 78 particles do not escape thecontainer element 4.

In FIG. 9F, the container element 4 is shown removed from a vessel 80with the distal end constricted. As can be seen there is generally noopening at the distal opening to allow further embolization of the clot78. The filament 6 is effectively closing the distal opening 20 as apurse string so that all the looped ends 106 of the braid are closetogether.

In other embodiments, a filament catheter 82 is included in the device2. A filament catheter 82 can provide several advantages. First, it canprovide axial support to the device 2 as the filament 6 is beingcinched. The support may hold the distal end 16 of the device 2 in afixed position during the distal opening 20 closure. Second, it canfacilitate in the deployment and retraction of the container element 4in the vessel. In the configurations where the container element 4 is abraid, the filament 6 catheter can be used to stretch the braid andthereby reduce its diameter by applying a distally acting tension on thebraid. Third, it can keep the arms 28, 30 constrained as they are insideor outside of the container element 4.

FIG. 10A shows the filament catheter 82 within the intermediate catheter72 and the distal opening 20 in the closed configuration. The containerelement 4 is completely within the intermediate catheter 72 in thisconfiguration and the intermediate catheter 72 can be advanced to thetarget vessel 80 in this configuration. In this embodiment, the filamentcatheter 82 is shown external to the container element 4. Alternatively,the filament catheter 82 could be within the lumen of the containerelement 4. In FIG. 10B, the intermediate catheter 72 has been retractedwhile the filament catheter 82 remained in the same location.Alternatively, the filament catheter 82 can be advanced while theintermediate catheter 72 remains in the same location. The filamentperimeter 48 is distal to the end of the intermediate catheter 72 and isstill in the closed configuration with the proximal end of the containerelement 4 still within the intermediate catheter 72. It should be notedthat the amount of closure of the distal opening 20 can be less or morethan what is shown. For example, the distal opening 20 can be closedmore so that the container element 4 at the filament perimeter 48touches itself and forms a full or partial seal at the distal opening20. In FIG. 10C, the filament 6 has been advanced and the distal opening20 is in the open configuration. The filament perimeter 48 is opened toapproximately the size of the vessel diameter and the container istherefore opened as well.

Turning now to FIG. 11A-11K, the use of the invented device 2 and methodwill be shown. FIGS. 11A-11F show a series of steps that is similar towhat may be currently practiced in thrombectomy procedures. In FIG. 11A,a clot 78 is shown in a vessel 80 such as a middle cerebral artery. Anintermediate catheter 72 has been advanced to the target vessel 80 asshown. In FIG. 11B, a microcatheter 74 has been advanced and a guidewire84 has been advanced so that it traverses the clot 78. In FIG. 11C, themicrocatheter 74 follows the guidewire 84 and traverses the clot 78.Contrast may be injected through the microcatheter 74 at these steps toconfirm its location with fluoroscopy. The guidewire 84 is removed fromthe microcatheter 74 in FIG. 11D. In FIG. 11E, a clot engagement element58 such as a stent retriever is inserted into the microcatheter 74 untilits tip extends distally from the end of the microcatheter 74. In FIG.11F, the microcatheter 74 is retracted and the stent retriever expandsinto the clot 78 and grabs it so that it can be pulled with the stentretriever. In a typical thrombectomy procedure the stent retriever isnow pulled along with the microcatheter and intermediate catheter 72.They can be pulled through the vessel and into a silicon ballooncatheter in the carotid. While this can remove the clot it can alsocreate fragmentation and distal embolization of the clot as describedabove.

FIGS. 11G-11K show the use of an embodiment of part of the inventeddevice 2 and method which can reduce the problems associated with justpulling the clot engagement element 58 and bare non-covered clot 78 outthrough the vessel 80.

In FIG. 11G, the intermediate catheter 72 and microcatheter 74 areremoved, leaving the stent retriever behind in the vessel 80 with theclot 78. Monorail type catheters (e.g. Rapid Exchange) may be usedinstead of over-the-wire catheters for any of the catheters describedherein to make exchanges of the catheters and wires easier.Alternatively, the intermediate catheter 72 can be left in placeproximal to the clot 78 and the stent retriever. In this embodiment thedevice 2 can be fed into the existing intermediate catheter 72 and theremaining steps of the described procedure can be followed.

In FIG. 11H, a new intermediate catheter 72 or the pre-existingintermediate catheter 72 with the device 2 is inserted onto the stentretriever wire and advanced to the target vessel. As described amonorail style catheter may be used. In at least some embodiments, thestent retriever wire is inserted through a hole at the proximal end ofthe container element such that the wire extends through the lumen ofthe container element 4. In other embodiments the hole may besignificantly larger such that the container element 4 does not come toa closed end like a wind sock. The filament 6 is within the intermediatecatheter 72 and is in the closed configuration.

In FIG. 11I, the intermediate catheter 72 is retracted and the containerelement 4 is opened in the vessel 80. The filament perimeter 48 expandsmanually or automatically such that it approximates the vessel 80 innerdiameter. In some embodiments, the container element 4 or filament 6significantly reduces or occludes blood flow through the vessel tofurther prevent distal embolization of the clot. The full or partialocclusion of the vessel may additionally prevent the need for aspirationor a silicone balloon catheter in the carotid artery. In otherembodiments, the container element 4 may only slightly limit the bloodflow. The filament perimeter 48 and distal opening 20 may open more orless than is shown. For example, the filament perimeter 48 can be openedto provide a positive radial force on the vessel 80 and further ensureflow arrest.

In FIG. 11J, the stent retriever and clot 78 are pulled through thedistal opening 20 and into the container element 4. Since the filamentperimeter 48 may approximate the diameter of the target vessel 80, itacts like a funnel that the stent retriever and clot 78 are pulled into.The clot 78 is fully within the container element 4. In someembodiments, the container element 4 is connected to the filamentcatheter 82 along some portion of its length. For example, the proximalend of the container element 4 may be connected to the filament catheter82 so it is not free floating. Alternatively, the entire length of thecontainer element 4 may be connected or integrated into the filamentcatheter 82.

In FIG. 11K, the filament perimeter 48 at the end of the device 2 isclosed by pulling the arms 28, 30. The distal opening 20 of thecontainer element 4 is therefore approximated and clot 78 is fullycontained within the container element 4. At this point the device 2with the clot 78 can be pulled from the vessel 80 and there may be areduced likelihood of distal embolization since the clot is contained.The device 2 may then be withdrawn from the patient.

In FIGS. 12A and 12B, alternative embodiments of the device 2 are shown.The filaments 6 are on the outside of the container element 4 in theseembodiments and additionally are routed within a filament catheter 82.The filament catheter 82 can hold the distal end 16 of the containerelement 4 in place as the tension is applied to the filaments 6 and thedistal opening 20 is closed. Additionally, the filament catheter 82 canprovide tension on the distal end 16 of the container element 4 suchthat the container element 4 can be stretched by pulling the proximalend of the container element 4 while holding the filament catheter 82stationary or by pushing the distal end 16 of the container element 4with the filament catheter 82 while holding the proximal end stationaryor some combination therein. The filament catheter 82 may be comprisedof any suitable catheter or tube material, such as nitinol, stainlesssteel, Pebax, PEEK, braided polyimide composite, or any other suitableconstruction. In some embodiments the filament catheter 82 can be aclosed wound coil. In some embodiments there is a filament catheter 82for each arm 28, 30. While the filament catheter 82 is shown on theoutside of the container element 4 in FIGS. 12A and 12B, it can also bewithin the inner diameter of the container element 4.

FIGS. 10-11 and FIG. 12 show similar devices having features which areincorporated for each other. For example, both show the containingelement 4 being free of attachments to the constraining catheter 8 andthat the intermediate catheter 72 has the secondary lumen with the firstfilament 6 extending through the secondary lumen. Further still, bothdevices show the intermediate catheter 72 positioned in the lumen 24 ofthe constraining catheter 8 with the intermediate catheter 72 beingmovable relative to the constraining catheter 8 so that relative motioncan move the containing element 4 to the released position (such asmoving the intermediate catheter 72 distally relative to theconstraining catheter 8). The devices 2 do differ in some respects inthat the device 2 of FIGS. 10 and 11 is free of attachments to theintermediate catheter 72 while in FIG. 12 the containing element 4 iscoupled to the intermediate catheter 72 for a length of at least 5 mm.

FIGS. 10-12 show embodiments where the filament 6 may include thefeatures of any of the other embodiments described herein. For example,the filament 6 may having the leading portion which will still emergefrom the constraining catheter 8 in the manner describe above eventhough the container element 4 is not attached to the constrainingcatheter 8. Of course, a feature such as the inverted portion is notimplicitly included in the embodiment of FIG. 10A-10C while the featuresof the closed position would be implicitly included in the embodimentsof FIGS. 10-12 . It is also understood that in the interest of brevitythat some claims are omitted when considering method claims similar todevice claims and vice versa. Thus, either method or device claims somissing still form part of the present invention even when notspecifically claimed.

In FIG. 13A-13B, an embodiment of the device 2 and method are shown. InFIG. 13A, a container element 4 is shown with a distal opening 20. Thecontainer element 4 may be braided construction, stent construction,framed cage construction, or any other suitable structure. The containerelement 4 is generally tubular and has a distal end with a distalopening 20 as well as at least one flap 88. The flap 88 is a piece whichextends distally past the distal opening 20 and has a flexing area 86. Afilament 6 is attached to the flap 88 at the filament 6 connection. Thefilament 6 may be a wire such as a stainless steel, nitinol, plastic, orsuture. The filament 6 may be connected to the flap 88 by a connection90 as shown or by welding, heat bonding, mechanical swaging, or anyother suitable process. In FIG. 13A, the flap 88 is in an unactuatedstate and there is minimal tension on the arm 28. Therefore, the distalopening 20 is generally open and may receive clots 78 or other materialthrough the distal opening 20. When the user is ready to contain thematerials in the container element 4, tension may be applied to the arm28. The tension creates a force on the flap 88 that causes it to bendabout the flexing area 86. In FIG. 13B, the flap 88 is rotated about 30degrees and is thereby partially closing the distal opening 20. In FIG.13C, additional tension is applied to the arm 28 and the distal opening20 is primarily covered by the flap 88 that has been rotated and flexedinto position. In some embodiments, the flap 88 may be comprised of thesame material as the container element 4 (integrally formed).Alternatively, the flap 88 may be a separate component that is connectedto the container element 4 at the flexing area 86. The connection may bea hinged connection (such as a living hinge) such that the flap 88 isprimarily free to rotate about the flexing area 86. In some embodiments,a more rigid material may be applied to the flap 88 so that it does notcrumple when the arm 28 is in tension. This may include adding fabric orplastic to the flap 88. In FIG. 13D, an alternative embodiment is shownwith more than one flap 88. Three flaps 88 are shown each with their ownfilament 6 but any number of other flaps 88 may be contemplated such asbetween 1 to 10 flaps or 2 to 4 flaps. The filaments 6 may be tensionedat the same time or individually. Thus, any number of folding patternsmay be contemplated. The flaps 88 may act like anatomical valve flapswhich meet at the longitudinal axis LA of the container element 4. Theflaps 88 do not need to be symmetric necessarily and can each be uniqueshapes. The shape of the flap 88 may be designed so that when all theflaps 88 are closed, the distal opening 20 of the container element 4 ismostly covered and materials within the container element 4 are trappedin place.

In any of the embodiments described herein aspiration may additionallybe applied within the device 2 to further assist in capturing the clot78. The aspiration may be connected to the intermediate catheter 72,constraining catheter 8, container element 4, or filament 6 catheter. Inembodiments where aspiration is applied to the container element 4, thepieces of the clot 78 may be sucked into the container element 4. Theaspiration reverses the blood flow so that it goes proximally. This maybe useful especially in embodiments where the device 2 provides localflow arrest so that the suction only comes from the distal side of theclot 78 and ensures that even if the clot 78 breaks apart it will notdistally embolize. The aspiration could be applied during certain stepsin the procedure outlined above such as when the clot engagement element58 is being deployed and then retracted into the container element 4.Alternatively, the use of aspiration may obviate the need for the clotengagement element 58. Aspiration may be used to suck the clot 78 intothe container element 4 without using a separate retriever. In stillother embodiments an agitator mechanism may be used to break up the clotand the aspiration then sucks the broken up pieces into the containerelement 4. The agitator may be mechanical such as a spinning or axiallysliding element that contacts the clot and breaks it into smaller piecesthat can be sucked up. Alternatively, the agitator may be vibratory orultrasonic such that the clot breaks apart. Aspiration may be achievedwith the use of a syringe or a vacuum source connected to the device 2.In some embodiments, the aspiration catheter 76 has a connectedmorcellating tip that is capable of breaking up clots 78. The aspirationcatheter 76 can pull the clot 78 into the container element 4 and thenthe distal opening 20 can be closed. The morcellating tip can be used toemulsify or break down the clot into smaller pieces which can be suckedthrough the aspiration catheter 76. Once the clot 78 material is nolonger within the container element 4, the distal opening 20 can beopened and the aspiration catheter 76 can be advanced to engage withstill more clot 78. This process can be repeated any number of times. Insome embodiments the same procedure is used for a stent retriever.

In still other embodiments, the container element 4 may not have anactive closing element such as the filament 6 described herein butinstead may be passively closed. The container element 4 may be shapeset such that it is a long tube as shown in the figures but at thedistal end 16 the container element 4 may funnel back to a constrictedshape when it is deployed. A separate frame element may be used toactively hold the container element 4 open when it is ready to acceptthe clot engagement element 58 being retracted within the containerelement 4. Once it is within the container element 4, the frame can bemoved axially to allow the container element 4 to constrict back to itsshape set profile. This may allow the opening and closing of the distalend 16 of the container element 4 by sliding a frame element distallyand proximally.

In some embodiments, the device 2 may contain all or only a portion ofthe devices described herein. For example, the device 2 may include aclot engagement element 58 such as a stent retriever or aspirationcatheter. Alternatively, the device 2 may only include the containerelement 4 and filament 6 and the device 2 may be used with an existingoff-the-shelf available stent retriever. In such an embodiment, thecontainer element 4 and filament 6 may be sized to accept such aretriever. The device 2 may be inserted into the body after the stentretriever has been deployed and captured the clot. In this way it is astand-alone system for capturing the clot that includes using other clotengagement elements. Any number of other configurations of the devicesdescribed herein are contemplated.

The device 2 can have a variety of shapes and sizes serving as aplatform for any type of thrombectomy, embolectomy, or foreign body,calculi or tissue removal in any part of the body or vessel. The device2 may provide proximal support for placement of distal devices such asrheolytic catheters, suction devices, graspers, balloons such as aFogarty balloon, wire snares, stent retrievers, etc. for any size tubeor vessel including arteries, veins, ureters, airways, bile ducts, andhollow viscous for retrieval of material.

The devices and methods described within may be used in any number ofother surgical procedure. For example, peripheral blood clots may belikewise removed with such a system. Any number of other suitableapplications may use such a device 2 for contained removal of a tissue,foreign body, calculi or other objects within a tubular contained spaceor even within non-tubular or non-contained spaces.

The names and labels applied to the various components and parts shouldnot be considered limiting to the scope of the invented device andmethod. For example, the term filament used herein may beinterchangeably used with snare, wire, ribbon, coil, elongate member, orany other suitable term. The term catheter is used to describe anelongate member with a distal and proximal end with a lumen extendingthere through. The terms intermediate catheter, constraining catheter,filament catheter, guide catheter, and micro catheter may often be usedinterchangeably. The term container element may often be interchangeablyused with bag, containing element, container element, pouch, or anyother suitable term. When referring to the opening of the distalopening, the terms releasing, deploying, opening, and expanding may beused interchangeably. When referring to the closure of the distalopening the terms cinching, closing, constraining, collapsing,constricting, snaring, or any other suitable term may often be usedinterchangeably. When referring to the radial constraining of thecontainer element by catheters, vessels, or filaments, the termsconstraining, restricting, containing, or constricting may also often beused interchangeably. The term filament perimeter may be usedinterchangeably with concave portion.

Although embodiments of various methods and devices are described hereinin detail with reference to certain versions, it should be appreciatedthat other versions, embodiments, methods of use, and combinationsthereof are also possible. Therefore, the spirit and scope of theappended claims should not be limited to the description of theembodiments contained herein.

1. A device for removing occlusive material from a blood vessel, thedevice comprising: a constraining catheter; a containing elementconfigurable into each of a collapsed configuration and an expandedconfiguration, said containing element at least partially encompassed bysaid constraining catheter when in said collapsed configuration, saidcontaining element further comprising an expandable interior chamber forcontaining said occlusive material and an outer wall portion adapted torestrict antegrade flow in said blood vessel when in use, wherein adistal portion of said containing element in said collapsedconfiguration comprises a filament extending distal of said outer wallportion, wherein, as said containing element expands towards saidexpanded configuration when released from said constraining catheter,said filament biases towards an unbiased shape that causes said filamentto retract proximally into said distal portion and opens said distalportion; and an actuator operatively coupled to said distal portion forreducing an area of a distal opening of said distal portion aftercapturing said occlusive material within said chamber.